Patent Application
20240150789
This application includes a Sequence Listing filed electronically as an XML file named 901513172SEQ, created on Oct. 28, 2023, with a size of 65,416 bytes. The Sequence Listing is incorporated herein by reference.
The present disclosure is directed, in part, to cytomegalovirus vectors encoding fusion proteins comprising Mycobacterium tuberculosis (Mtb) antigens, nucleic acid molecules encoding the same, cytomegalovirus vectors comprising nucleic acid molecules, compositions comprising the same, and methods of eliciting an immune response against tuberculosis.
Tuberculosis (TB) is a global health problem resulting in 8 million new cases and 2 million deaths each year. The emergence of multi-drug and totally-drug resistant strains of TB only makes this problem more severe. The life cycle of Mtb has 3 stages. In the acute phase following initial infection the bacteria replicate in the host and virulence factors are expressed, leading to the generation of an immune response by the host. As the immune response begins to control the infection, the Mtb enters a latent, asymptomatic state in which the bacteria become non-replicating and are encased in granulomas. The bacterium can persist in this latent state in infected individuals for many years, making diagnosis and treatment of disease difficult. In some cases, the bacteria are reactivated and begin replicating again, leading back to the disease state. Reactivation can occur for numerous reasons, including immune suppression caused by diseases such as HIV, treatments such as chemotherapy, or the weakening of the immune system due to aging. An estimated 2 billion people are latently infected with Mtb worldwide, and reactivation of latent Mtb accounts for most new cases of active TB disease. Reactivation is associated with inflammation, necrosis and cavitation of the lung, a process that results in draining of the lesions into the bronchus. Aerosols generated when individuals with bronchial lesions cough causes dissemination of the Mtb organism to uninfected, susceptible persons, and the transmission cycle is thus maintained.
The only currently available vaccine against TB, Mycobacterium bovis (Bacille Calmette-Guérin) (BCG), was first introduced in 1921. BCG has been widely utilized and while studies show that for some purposes BCG is effective (e.g. against disseminated TB in infants), it is known to be ineffective with respect to preventing the development, persistence and reactivation of latent TB in adults. There is an ongoing need to develop improved, more effective vaccines against TB.
Use of cytomegalovirus (CMV) vectors (e.g., Rhesus CMV (RhCMV) and human CMV (HCMV)) has particular advantages. First, CMV elicits an astoundingly high frequency (steady-state) T cell response, at least an order of magnitude higher than that of most non-persistent virus (it is not uncommon for CMV-specific T cells to encompass >20% of the circulating memory repertoire), and the representation of CMV-specific T cells (as it relates to CMV-driven non-CMV antigens) is even higher in tissues such as the lung and liver. In addition, the above responses persist indefinitely. CMV is also capable of re-infecting already chronically infected individuals, even in the face of pre-existing immune responses, and such re-infection with recombinant CMVs is also capable of inducing new responses to distinct CMV-encoded foreign proteins. CMV also engenders pathogenicity only in very specific situations of immune deficiency, immaturity, or seronegative pregnant women (its potential for disease is among the best documented among potential human pathogens). Finally, CMV infection is ubiquitous in most of humanity.
While vaccines are often effective to immunize individuals prophylactically or therapeutically against pathogen infection or human diseases, there is a need for improved vaccines and vectors. There is also a need for compositions and methods that produce an enhanced immune response. Likewise, while some immunotherapeutics are useful to modulate immune response in a patient, there remains a need for improved immunotherapeutic compositions and methods.
The present disclosure provides recombinant RhCMV or HCMV vectors comprising a nucleic acid sequence encoding an expressible Mtb antigen selected from Ag85A-Ag85B-Rv3407, Rv1733-Rv2626c, RpfA-RpfC-RpfD, Ag85B-ESAT6, and Ag85A-ESAT6-Rv3407-Rv2626c-RpfA-RpfD.
The present disclosure also provides pharmaceutical compositions comprising the recombinant RhCMV or HCMV vaccine vectors described herein and a pharmaceutically acceptable carrier.
The present disclosure also provides methods for treatment or prevention of tuberculosis comprising administering to a subject in need thereof at least one recombinant RhCMV or HCMV vaccine vector described herein.
The present disclosure also provides methods for eliciting an immune response to a Mtb antigen comprising administering to a subject in need thereof at least one recombinant RhCMV or HCMV vaccine vector described herein.
The present disclosure also provides methods for eliciting a CD8+ or CD4+ T cell response to a Mtb antigen comprising administering to a subject in need thereof at least one recombinant RhCMV or HCMV vaccine vector described herein.
The present disclosure also provides Mtb antigens selected from Ag85B-ESAT6 and Ag85A-ESAT6-Rv3407-Rv2626c-RpfA-RpfD.
The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting.
As used herein, the singular forms “a,” “an” and “the” include plural referents unless the context clearly dictates otherwise.
For recitation of numeric ranges herein, each intervening number there between with the same degree of precision is explicitly contemplated. For example, for the range of 6-9, the numbers 7 and 8 are contemplated in addition to 6 and 9, and for the range 6.0-7.0, the numbers 6.0, 6.1, 6.2, 6.3, 6.4, 6.5, 6.6, 6.7, 6.8, 6.9, and 7.0 are explicitly contemplated.
As used herein, “adjuvant” means any molecule added to any composition described herein to enhance the immunogenicity of the Mtb antigens.
As used herein, “coding sequence” or “encoding nucleic acid” means the nucleic acids (RNA or DNA molecule) that comprise a nucleotide sequence which encodes an Mtb antigen. The coding sequence can further include initiation and termination signals operably linked to regulatory elements including a promoter and polyadenylation signal capable of directing expression in the cells of an individual or mammal to which the nucleic acid is administered.
As used herein, “consensus” or “consensus sequence” means a polypeptide sequence based on analysis of an alignment of multiple subtypes of a particular Mtb antigen. Nucleic acid sequences that encode a consensus polypeptide sequence can be prepared. Vaccines comprising Mtb antigens that comprise consensus sequences and/or nucleic acid molecules that encode such antigens can be used to induce broad immunity against multiple subtypes or serotypes of a particular antigen. I some embodiments, the consensus sequence may be the most common sequence.
As used herein, “electroporation” means the use of a transmembrane electric field pulse to induce microscopic pathways (pores) in a bio-membrane; their presence allows biomolecules such as plasmids, oligonucleotides, siRNA, drugs, ions, and water to pass from one side of the cellular membrane to the other.
As used herein, “fragment” with respect to nucleic acid sequences, means a nucleic acid sequence or a portion thereof, that encodes a portion of an Mtb antigen capable of eliciting an immune response in a mammal that cross reacts with a full length wild type Mtb antigen. The fragments can be DNA fragments selected from at least one of the various nucleotide sequences that encode protein fragments set forth below. For example, polynucleotides may comprise at least about 15, 20, 30, 40, 50, 75, 100, 150, 200, 300, 400, 500 or 1000 or more contiguous nucleotides of one or more of the sequences disclosed herein as well as all intermediate lengths there between. It will be readily understood that “intermediate lengths”, in this context, means any length between the quoted values, such as 16, 17, 18, 19, etc.; 21, 22, 23, etc.; 30, 31, 32, etc.; 50, 51, 52, 53, etc.; 100, 101, 102, 103, etc.; 150, 151, 152, 153, etc.; including all integers through 200 to 500; 500 to 1,000, and the like.
As used herein, “fragment” or “immunogenic fragment” with respect to polypeptide sequences, means a portion of an MTB antigen capable of eliciting an immune response in a mammal that cross reacts with a full length wild type strain Mtb antigen. Fragments of consensus or wild type Mtb antigens can comprise at least 10%, at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90% or at least 95% of a consensus or wild type Mtb antigen. In some embodiments, fragments of consensus proteins can comprise at least 20 amino acids or more, at least 30 amino acids or more, at least 40 amino acids or more, at least 50 amino acids or more, at least 60 amino acids or more, at least 70 amino acids or more, at least 80 amino acids or more, at least 90 amino acids or more, at least 100 amino acids or more, at least 110 amino acids or more, at least 120 amino acids or more, at least 130 amino acids or more, at least 140 amino acids or more, at least 150 amino acids or more, at least 160 amino acids or more, at least 170 amino acids or more, at least 180 amino acids or more of a consensus or wild type protein.
As used herein, “genetic construct” refers to the DNA or RNA molecules that comprise a nucleotide sequence which encodes an Mtb antigen. The coding sequence includes initiation and termination signals operably linked to regulatory elements including a promoter and polyadenylation signal capable of directing expression in the cells of the individual to whom the nucleic acid molecule is administered.
As used herein, “expressible form” refers to gene constructs that contain the necessary regulatory elements operable linked to a coding sequence that encodes an Mtb antigen such that when present in the cell of the individual, the coding sequence will be expressed.
As used herein, “homology” refers to a degree of complementarity for nucleic acid molecules. There can be partial homology or complete homology (i.e., identity). A partially complementary sequence that at least partially inhibits a completely complementary sequence from hybridizing to a target nucleic acid is referred to using the functional term “substantially homologous.” When used in reference to a double-stranded nucleic acid sequence such as a cDNA or genomic clone, the term “substantially homologous” refers to a probe that can hybridize to a strand of the double-stranded nucleic acid sequence under conditions of low stringency. When used in reference to a single-stranded nucleic acid sequence, the term “substantially homologous” refers to a probe that can hybridize to (i.e., is the complement of) the single-stranded nucleic acid template sequence under conditions of low stringency.
As used herein, “identical” or “identity” in the context of two or more nucleic acids or polypeptide sequences, means that the sequences have a specified percentage of residues that are the same over a specified region. The percentage can be calculated by optimally aligning the two sequences, comparing the two sequences over the specified region, determining the number of positions at which the identical residue occurs in both sequences to yield the number of matched positions, dividing the number of matched positions by the total number of positions in the specified region, and multiplying the result by 100 to yield the percentage of sequence identity. In cases where the two sequences are of different lengths or the alignment produces one or more staggered ends and the specified region of comparison includes only a single sequence, the residues of single sequence are included in the denominator but not the numerator of the calculation. When comparing DNA and RNA, thymine (T) and uracil (U) residues can be considered equivalent. Identity and/or homology can be performed manually or by using a computer sequence algorithm such as BLAST or BLAST 2.0.
As used herein, “immune response” means the activation of a host's immune system, e.g., that of a mammal, in response to the introduction of an Mtb antigen. The immune response can be in the form of a cellular or humoral response, or both.
As used herein, “isolated” means that a polynucleotide is substantially away from other coding sequences, and that the nucleic acid segment does not contain large portions of unrelated coding DNA, such as large chromosomal fragments or other functional genes or polypeptide coding regions. Of course, this refers to the nucleic acid segment as originally isolated, and does not exclude genes or coding regions later added to the segment by the hand of man.
As used herein, “Mtb antigen” means an antigen from Mycobacterium tuberculosis, which may be an isolated antigen, or an antigen that forms part of a fusion protein with other antigen(s).
As used herein, “Mycobacteria” means a genus of aerobic intracellular bacterial organisms. Upon invasion of a host, these organisms survive within endosomal compartments of monocytes and macrophages. Human mycobacterial diseases include tuberculosis (caused by M. tuberculosis (Mtb)), Leprosy (caused by M. leprae), Baimsdale ulcers (caused by M. ulcerans), and other infections that can be caused by M. marinum, M. kansasii, M. scrofulaceum, M. szulgai, M. xenopi, M. fortuitum, M. haemophilum, M. chelonei, and M. intracelluare. Mycobacterium strains that were previously considered to be nonpathogenic (such as M. avium) are also now known to be major killers of immunosuppressed AIDS patients. The major response to Mycobacteria involves cell mediated hypersensitivity (DTH) reactions with T cells and macrophages playing major roles in the intracellular killing and walling off (or containing) of the organism (granuloma formation). A major T cell response involves CD4+ lymphocytes that recognize mycobacterial heat shock proteins and immunodominant antigens.
As used herein, “nucleic acid” or “oligonucleotide” or “polynucleotide” means at least two nucleotides covalently linked together, which has been isolated free of total genomic DNA of a particular species. Included within these terms are nucleic acid segments and smaller fragments of such segments, and also recombinant CMV vectors. The depiction of a single strand also defines the sequence of the complementary strand. Thus, a nucleic acid also encompasses the complementary strand of a depicted single strand. Many variants of a nucleic acid can be used for the same purpose as a given nucleic acid. Thus, a nucleic acid also encompasses substantially identical nucleic acids and complements thereof. A single strand provides a probe that can hybridize to a target sequence under stringent hybridization conditions. Thus, a nucleic acid also encompasses a probe that hybridizes under stringent hybridization conditions. Nucleic acids can be single stranded or double stranded, or can contain portions of both double stranded and single stranded sequence. The nucleic acid can be DNA, both genomic and cDNA, RNA, or a hybrid, where the nucleic acid can contain combinations of deoxyribo- and ribo-nucleotides, and combinations of bases including uracil, adenine, thymine, cytosine, guanine, inosine, xanthine hypoxanthine, isocytosine and isoguanine. Nucleic acids can be obtained by chemical synthesis methods or by recombinant methods. As will be understood by those skilled in the art, the nucleic acid molecules can include genomic sequences, extra-genomic and plasmid-encoded sequences and smaller engineered gene segments that express, or may be adapted to express, proteins, polypeptides, peptides and the like. Such segments may be naturally isolated, or modified synthetically by the hand of man.
As used herein, “operably linked” means that expression of a gene is under the control of a promoter with which it is spatially connected. A promoter can be positioned 5′ (upstream) or 3′ (downstream) of a gene under its control. The distance between the promoter and a gene can be approximately the same as the distance between that promoter and the gene it controls in the gene from which the promoter is derived. As is known in the art, variation in this distance can be accommodated without loss of promoter function.
As used herein, “promoter” means a synthetic or naturally-derived molecule which is capable of conferring, activating or enhancing expression of a nucleic acid in a cell. A promoter can comprise one or more specific transcriptional regulatory sequences to further enhance expression and/or to alter the spatial expression and/or temporal expression of same. A promoter can also comprise distal enhancer or repressor elements, which can be located as much as several thousand base pairs from the start site of transcription. A promoter can be derived from sources including viral, bacterial, fungal, plants, insects, and animals. A promoter can regulate the expression of a gene component constitutively, or differentially with respect to cell, the tissue or organ in which expression occurs or, with respect to the developmental stage at which expression occurs, or in response to external stimuli such as physiological stresses, pathogens, metal ions, or inducing agents.
As used herein, “signal peptide” and “leader sequence”, used interchangeably, refer to an amino acid sequence that can be linked at the amino terminus of an Mtb antigenic protein set forth herein. Signal peptides/leader sequences typically direct localization of a protein. Signal peptides/leader sequences used herein can facilitate secretion of the protein from the cell in which it is produced or anchor it in the membrane. Signal peptides/leader sequences are often cleaved from the remainder of the protein, often referred to as the mature protein, upon secretion from the cell. Signal peptides/leader sequences are linked at the N terminus of the protein.
As used herein, “stringent hybridization conditions” means conditions under which a first nucleic acid sequence (e.g., probe) will hybridize to a second nucleic acid sequence (e.g., target), such as in a complex mixture of nucleic acids. Stringent conditions are sequence-dependent and will be different in different circumstances. Stringent conditions can be selected to be about 5 to 10° C. lower than the thermal melting point (Tm) for the specific sequence at a defined ionic strength pH. The Tm can be the temperature (under defined ionic strength, pH, and nucleic concentration) at which 50% of the probes complementary to the target hybridize to the target sequence at equilibrium (as the target sequences are present in excess, at Tm, 50% of the probes are occupied at equilibrium). Stringent conditions can be those in which the salt concentration is less than about 1.0 M sodium ion, such as about 0.01 to 1.0 M sodium ion concentration (or other salts) at pH 7.0 to 8.3 and the temperature is at least about 30° C. for short probes (e.g., about 10 to 50 nucleotides) and at least about 60° C. for long probes (e.g., greater than about 50 nucleotides). Stringent conditions can also be achieved with the addition of destabilizing agents such as formamide. For selective or specific hybridization, a positive signal can be at least 2 to 10 times background hybridization. Exemplary stringent hybridization conditions include the following: 50% formamide, 5×SSC, and 1% SDS, incubating at 42° C., or, 5×SSC, 1% SDS, incubating at 65° C., with wash in 0.2×SSC, and 0.1% SDS at 65° C.
As used herein, “substantially complementary” means that a first sequence is at least 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 97%, 98% or 99% identical to the complement of a second sequence over a region of 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 180, 270, 360, 450, 540, or more nucleotides or amino acids, or that the two sequences hybridize under stringent hybridization conditions.
As used herein, “substantially identical” means that a first and second sequence are at least 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98% or 99% identical over a region of 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 180, 270, 360, 450, 540 or more nucleotides or amino acids, or with respect to nucleic acids, if the first sequence is substantially complementary to the complement of the second sequence.
As used herein, “tuberculosis” means a disease that is generally caused by Mycobacterium tuberculosis that usually infects the lungs. However, other “atypical” Mycobacteria such as M. kansasii may produce a similar clinical and pathologic appearance of disease. Transmission of M. tuberculosis occurs by the airborne route in confined areas with poor ventilation. In more than 90% of cases, following infection with M. tuberculosis, the immune system prevents development of disease from M. tuberculosis, often called, active tuberculosis. However, not all of the M. tuberculosis is killed and, thus tiny, hard capsules are formed. “Primary tuberculosis” is seen as disease that develops following an initial infection, usually in children. The initial focus of infection is a small subpleural granuloma accompanied by granulomatous hilar lymph node infection. Together, these make up the Ghon complex. In nearly all cases, these granulomas resolve and there is no further spread of the infection. “Secondary tuberculosis” is seen mostly in adults as a reactivation of previous infection (or reinfection), particularly when health status declines. The granulomatous inflammation is much more florid and widespread. Typically, the upper lung lobes are most affected, and cavitation can occur. Dissemination of tuberculosis outside of the lungs can lead to the appearance of a number of uncommon findings with characteristic patterns that include skeletal tuberculosis, genital tract tuberculosis, urinary tract tuberculosis, central nervous system (CNS) tuberculosis, gastrointestinal tuberculosis, adrenal tuberculosis, scrofula, and cardiac tuberculosis. “Latent” tuberculosis is an Mtb infection in an individual that can be detected by a diagnostic assay, such as, but not limited to a tuberculin skin test (TST) wherein the infection does not produce symptoms in that individual. “Active” tuberculosis is a symptomatic Mtb infection in a subject. Microscopically, the inflammation produced with TB infection is granulomatous, with epithelioid macrophages and Langhans giant cells along with lymphocytes, plasma cells, maybe a few polymorphonuclear cells, fibroblasts with collagen, and characteristic caseous necrosis in the center. The inflammatory response is mediated by a type IV hypersensitivity reaction, and skin testing is based on this reaction. In some examples, tuberculosis can be diagnosed by a skin test, an acid fast stain, an auramine stain, or a combination thereof. The most common specimen screened is sputum, but the histologic stains can also be performed on tissues or other body fluids.
As used herein, “variant” with respect to a nucleic acid means: i) a portion or fragment of a referenced nucleotide sequence; ii) the complement of a referenced nucleotide sequence or portion thereof; iii) a nucleic acid that is substantially identical to a referenced nucleic acid or the complement thereof; or iv) a nucleic acid that hybridizes under stringent conditions to the referenced nucleic acid, complement thereof, or a sequences substantially identical thereto.
As used herein, “variant” with respect to a peptide or polypeptide means that it differs in amino acid sequence by the insertion, deletion, or conservative substitution of amino acids, but retains at least one biological activity. Variant can also mean a protein with an amino acid sequence that is substantially identical to a referenced protein with an amino acid sequence that retains at least one biological activity. A conservative substitution of an amino acid, i.e., replacing an amino acid with a different amino acid of similar properties (e.g., hydrophilicity, degree and distribution of charged regions) is recognized in the art as typically involving a minor change. Amino acid substitutions that are compatible with biological function are understood to depend on the relative similarity of the amino acids, and particularly the side chains of those amino acids, as revealed by the hydrophobicity, hydrophilicity, charge, size, and other properties. The term “variant” also encompasses homologous genes of xenogeneic origin.
As used herein, “CMV vector” means a CMV nucleic acid molecule as introduced into a host cell, thereby producing a transformed host cell. A CMV vector may include nucleic acid sequences that permit it to replicate in a host cell, such as an origin of replication. A CMV vector may also include one or more selectable marker gene and other genetic elements known in the art.
The present disclosure provides recombinant RhCMV or HCMV vectors comprising a nucleic acid molecule encoding an expressible Mtb antigen selected from Ag85A-Ag85B-Rv3407, Rv1733-Rv2626c, RpfA-RpfC-RpfD, Ag85B-ESAT6, and Ag85A-ESAT6-Rv3407-Rv2626c-RpfA-RpfD. In some embodiments, the nucleic acid molecule encoding any particular Mtb antigen can be a mycobacterial sequence, a bacterial codon optimized sequence (such as an E. coli optimized sequence), or a mammalian optimized sequence (such as a human optimized sequence). Methods of codon optimization (whether for bacterial or mammalian) are well known to the skilled artisan.
In any of the embodiments of the nucleic acid molecules set forth herein, the individual Mtb nucleic acid sequences can be present in any order. For example, for a fusion protein comprising Ag85A, Ag85B, and Rv3407 antigens, the first (or N-terminal) nucleic acid molecule may encode Ag85A, Ag85B, or Rv3407; the second nucleic acid molecule may encode Ag85A, Ag85B, or Rv3407 (whichever one is not the first Mtb antigen); and the third nucleic acid molecule may encode Ag85A, Ag85B, or Rv3407 (whichever one is not the first or second Mtb antigen). Likewise for every nucleic acid molecule disclosed herein.
Additional coding or non-coding sequences may, but need not, be present within a polynucleotide of the present invention, and a polynucleotide may, but need not, be linked to other molecules and/or support materials.
Polynucleotides may comprise a native sequence (e.g., an endogenous sequence that encodes a CMV or TB protein or a portion thereof) or may comprise a variant, or a biological or antigenic functional equivalent of such a sequence.
A nucleotide sequence encoding Ag85A is shown in Table 1 as SEQ ID NO:1, and an amino acid sequence of Ag85A is shown in Table 1 as SEQ ID NO:2.
A nucleotide sequence encoding Ag85B is shown in Table 1 as SEQ ID NO:3, and an amino acid sequence of Ag85B is shown in Table 1 as SEQ ID NO:4.
A nucleotide sequence encoding Rv3407 is shown in Table 1 as SEQ ID NO:5, and an amino acid sequence of Rv3407 is shown in Table 1 as SEQ ID NO:6.
A nucleotide sequence encoding Rv1733 is shown in Table 1 as SEQ ID NO:7, and an amino acid sequence of Rv1733 is shown in Table 1 as SEQ ID NO:8.
A nucleotide sequence encoding Rv2626c is shown in Table 1 as SEQ ID NO:9, and an amino acid sequence of Rv2626c is shown in Table 1 as SEQ ID NO:10.
A nucleotide sequence encoding RpfA is shown in Table 1 as SEQ ID NO:11, and an amino acid sequence of RpfA is shown in Table 1 as SEQ ID NO:12.
A nucleotide sequence encoding RpfC is shown in Table 1 as SEQ ID NO:13, and an amino acid sequence of RpfC is shown in Table 1 as SEQ ID NO:14.
A nucleotide sequence encoding RpfD is shown in Table 1 as SEQ ID NO:15, and an amino acid sequence of RpfD is shown in Table 1 as SEQ ID NO:16.
A nucleotide sequence encoding ESAT-6 is shown in Table 1 as SEQ ID NO:17, and an amino acid sequence of ESAT-6 is shown in Table 1 as SEQ ID NO:18.
All sequences shown in Table 1 are derived from HCMV.
In some embodiments, the fusion protein comprises Ag85A, Ag85B, and Rv3407 antigens. In some embodiments, the fusion protein comprises Rv1733 and Rv2626c antigens. In some embodiments, the fusion protein comprises RpfA, RpfC, and RpfD antigens. In some embodiments, the fusion protein comprises Ag85B and ESAT6 antigens. In some embodiments, the fusion protein comprises Ag85A, ESAT6, Rv3407, Rv2626c, RpfA, and RpfD antigens.
In any of the embodiments of fusion proteins set forth herein, the individual Mtb antigens can be present in any order. For example, for a fusion protein comprising Ag85A, Ag85B, and Rv3407 antigens, the first (or N-terminal) antigen may be Ag85A, Ag85B, or Rv3407; the second antigen may be Ag85A, Ag85B, or Rv3407 (whichever one is not the first Mtb antigen); and the third antigen may be Ag85A, Ag85B, or Rv3407 (whichever one is not the first or second Mtb antigen). Likewise for every fusion protein disclosed herein.
Individual Mtb antigens may be linked together in a C-terminus to N-terminus or N-terminus to C-terminus manner without any linker. Alternately, a linker may be present between any two Mtb antigens within any of the fusion proteins disclosed herein. In some embodiments, the linker is a segment of DNA optionally containing one or more restrictions sites, wherein the linker is inserted between nucleic acid molecules encoding two Mtb antigens of any of the fusion proteins disclosed herein.
In some embodiments, the fusion protein comprises Ag85A-Ag85B-Rv3407 (Construct A; see Table 2). The nucleotide sequence is SEQ ID NO:19, and the corresponding amino acid sequence is SEQ ID NO:20.
In some embodiments, the fusion protein comprises Rv1733-Rv2626c (Construct B; see Table 2). The nucleotide sequence is SEQ ID NO:21, and the corresponding amino acid sequence is SEQ ID NO:22.
In some embodiments, the fusion protein comprises RpfA-RpfC-RpfD (Construct C; see Table 2). The nucleotide sequence is SEQ ID NO:23, and the corresponding amino acid sequence is SEQ ID NO:24.
In some embodiments, the fusion protein comprises Ag85B-ESAT6 (Construct D; see Table 2). The nucleotide sequence is SEQ ID NO:25, and the corresponding amino acid sequence is SEQ ID NO:26.
In some embodiments, the fusion protein comprises Ag85A-ESAT6-Rv3407-Rv2626c-RpfA-RpfD (Construct E; see Table 2). The nucleotide sequence is SEQ ID NO:27 or SEQ ID NO:28, and the corresponding amino acid sequence is SEQ ID NO:29 or SEQ ID NO:30.
Any Mtb antigen, including any Mtb antigen within any of the fusion proteins described herein, can have an amino acid sequence that is 100%, or from 70% to 99.9%, identical to the particular amino acid sequence listed in Tables 1 and 2. The amino acid sequence of any individual Mtb antigen, including any Mtb antigen within any of the fusion proteins described herein, can be at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to the particular amino acid sequence listed in Tables 1 and 2. Identity or similarity with respect to an amino acid or nucleotide sequence is defined herein as the percentage of amino acid residues (or nucleotide residues as the case may be) in the particular Mtb antigen that are identical (i.e., same residue) with the amino acid or nucleotide sequence for the Mtb antigen shown in Tables 1 and 2, after aligning the sequences and introducing gaps, if necessary, to achieve the maximum percent sequence identity. Percent sequence identity can be determined by, for example, the Gap program (Wisconsin Sequence Analysis Package, Version 8 for Unix, Genetics Computer Group, University Research Park, Madison WI), using default settings, which uses the algorithm of Smith and Waterman (Adv. Appl. Math., 1981, 2, 482-489). Any amino acid number calculated as a % identity can be rounded up or down, as the case may be, to the closest whole number.
Optimal alignment of sequences for comparison can also be conducted using the Megalign program in the Lasergene suite of bioinformatics software (DNASTAR, Inc., Madison, Wis.), using default parameters. This program embodies several alignment schemes described in the following references: Dayhoff, M. 0. (1978) A model of evolutionary change in proteins—Matrices for detecting distant relationships. In Dayhoff, M. O. (ed.) Atlas of Protein Sequence and Structure, National Biomedical Research Foundation, Washington D.C. Vol. 5, Sunni. 3, pp. 345-358; Hein J. (1990) Unified Approach to Alignment and Phylogenes pp. 626-645 Methods in Enzymology vol. 183, Academic Press, Inc., San Diego, Calif; Higgins, D. G. and Sharp, P. M. (1989) CABIOS 5:151-153; Myers, E. W. and Muller W. (1988) CABIOS 4:11-17; Robinson, E. D. (1971) Comb. Theor 11:105; Santou, N. Nes, M. (1987) Mol. Biol. Evol. 4:406-425; Sneath, P. H. A. and Sokal, R. R. (1973) Numerical Taxonomy—the Principles and Practice of Numerical Taxonomy, Freeman Press, San Francisco, Calif; Wilbur, W. J. and Lipman, D. J. (1983) Proc. Natl. Acad., Sci. USA 80:726-730.
Alternately, optimal alignment of sequences for comparison may be conducted by the local identity algorithm of Smith and Waterman (1981) Add. APL. Math 2:482, by the identity alignment algorithm of Needleman and Wunsch (1970) J. Mol. Biol. 48:443, by the search for similarity methods of Pearson and Lipman (1988) Proc. Natl. Acad. Sci. USA 85: 2444, by computerized implementations of these algorithms (GAP, BESTFIT, BLAST, FASTA, and TFASTA in the Wisconsin Genetics Software Package, Genetics Computer Group (GCG), 575 Science Dr., Madison, Wis.), or by inspection.
Suitable examples of algorithms for determining percent sequence identity and sequence similarity are the BLAST and BLAST 2.0 algorithms, which are described in Altschul et al. (1977) Nucl. Acids Res. 25:3389-3402 and Altschul et al. (1990) J. Mol. Biol. 215:403-410, respectively. BLAST and BLAST 2.0 can be used, for example with the parameters described herein, to determine percent sequence identity for the polynucleotides and polypeptides of the invention. Software for performing BLAST analyses is publicly available through the National Center for Biotechnology Information. In one illustrative example, cumulative scores can be calculated using, for nucleotide sequences, the parameters M (reward score for a pair of matching residues; always >0) and N (penalty score for mismatching residues; always <0). For amino acid sequences, a scoring matrix can be used to calculate the cumulative score. Extension of the word hits in each direction are halted when: the cumulative alignment score falls off by the quantity X from its maximum achieved value; the cumulative score goes to zero or below, due to the accumulation of one or more negative-scoring residue alignments; or the end of either sequence is reached. The BLAST algorithm parameters W, T and X determine the sensitivity and speed of the alignment. The BLASTN program (for nucleotide sequences) uses as defaults a wordlength (W) of 11, and expectation (E) of 10, and the BLOSUM62 scoring matrix (see Henikoff and Henikoff (1989) Proc. Natl. Acad. Sci. USA 89:10915) alignments, (B) of 50, expectation (E) of 10, M=5, N=−4 and a comparison of both strands.
In some embodiments, the “percentage of sequence identity” is determined by comparing two optimally aligned sequences over a window of comparison of at least 20 positions, wherein the portion of the polynucleotide or polypeptide sequence in the comparison window may comprise additions or deletions (i.e., gaps) of 20 percent or less, usually 5 to 15 percent, or 10 to 12 percent, as compared to the reference sequences (which does not comprise additions or deletions) for optimal alignment of the two sequences. The percentage is calculated by determining the number of positions at which the identical nucleic acid bases or amino acid residue occurs in both sequences to yield the number of matched positions, dividing the number of matched positions by the total number of positions in the reference sequence (i.e., the window size) and multiplying the results by 100 to yield the percentage of sequence identity.
Any Mtb antigen, including any Mtb antigen within any of the fusion proteins described herein, can be fragments of the particular amino acid sequence listed in Table 1. The amino acid sequence of any individual Mtb antigen, including any Mtb antigen within any of the fusion proteins described herein, can be missing consecutive amino acids constituting at least 20%, at least 15%, at least 10%, at least 5%, at least 4%, at least 3%, at least 2%, or at least 1%, of the particular amino acid sequence listed in Table 1. The omitted consecutive amino acids may be from the C-terminus or N-terminus portion of the antigen. Alternately, the omitted consecutive amino acids may be from the internal portion of the antigen, thus retaining at least its C-terminus and N-terminus amino acids of the antigen.
Any Mtb antigen, including any Mtb antigen within any of the fusion proteins described herein, can have one or more amino acid additions, deletions, or substitutions compared to the particular amino acid sequence listed in Table 1. Any individual Mtb antigen, including any Mtb antigen within any of the fusion proteins described herein, can have at least one, at least two, at least three, at least four, at least five, at least six, at least seven, at least eight, at least nine, at least ten, at least eleven, or at least twelve amino acid additions, deletions, or substitutions compared to the particular amino acid sequence listed in Table 1. The amino acid additions, deletions, or substitutions can take place at any amino acid position within the Mtb antigen.
Where a particular Mtb antigen, including any Mtb antigen within any of the fusion proteins described herein, comprises at least one or more substitutions, the substituted amino acid(s) can each be, independently, any naturally occurring amino acid or any non-naturally occurring amino acid. Thus, a particular Mtb antigen may comprise one or more amino acid substitutions that are naturally occurring amino acids and/or one or more amino acid substitutions that are non-naturally occurring amino acids. Individual amino acid substitutions are selected from any one of the following: 1) the set of amino acids with nonpolar sidechains, for example, Ala, Cys, Ile, Leu, Met, Phe, Pro, Val; 2) the set of amino acids with negatively charged side chains, for example, Asp, Glu; 3) the set of amino acids with positively charged sidechains, for example, Arg, His, Lys; and 4) the set of amino acids with uncharged polar sidechains, for example, Asn, Cys, Gln, Gly, His, Met, Phe, Ser, Thr, Trp, Tyr, to which are added Cys, Gly, Met and Phe. Substitutions of a member of one class with another member of the same class are contemplated herein. Naturally occurring amino acids include, for example, alanine (Ala), arginine (Arg), asparagine (Asn), aspartic acid (Asp), cysteine (Cys), glutamine (Gln), glutamic acid (Glu), glycine (Gly), histidine (His), isoleucine (Ile), leucine (Leu), lysine (Lys), methionine (Met), phenylalanine (Phe), proline (Pro), serine (Ser), threonine (Thr), tryptophan (Trp), tyrosine (Tyr), and valine (Val). Non-naturally occurring amino acids include, for example, norleucine, omithine, norvaline, homoserine, and other amino acid residue analogues such as those described in Ellman et al., Meth. Enzym., 1991, 202, 301-336. To generate such non-naturally occurring amino acid residues, the procedures of Noren et al., Science, 1989, 244, 182 and Ellman et al., supra, can be used. Briefly, these procedures involve chemically activating a suppressor tRNA with a non-naturally occurring amino acid residue followed by in vitro transcription and translation of the RNA.
The Mtb antigens, including any Mtb antigen within any of the fusion proteins described herein, which are modified as described herein retain their ability to elicit an immune response against Mycobacterium tuberculosis. That is, modification of a particular Mtb antigen, including any Mtb antigen within any of the fusion proteins described herein, will still allow the resultant Mtb antigen, or fusion protein comprising the same, to elicit an immune response against Mycobacterium tuberculosis.
The present disclosure also provides nucleic acid molecules encoding any of the fusion proteins described herein that comprise at least three Mycobacterium tuberculosis (Mtb) antigens. The nucleic acid molecules described herein and in Tables 1 and 2 are representative. The specific sequences recited in Table 1 are simply one example of a nucleic acid molecule that can encode a particular Mtb antigen within a fusion protein. One skilled in the art having knowledge of the genetic code can routinely prepare and design a plethora of nucleic acid molecules encoding the same Mtb antigen. The length and nucleotide content of any particular nucleic acid molecule is dictated by the desired amino acid sequence of the encoded Mtb antigen. The nucleic acid molecule sequences shown in Tables 1 and 2 are DNA, although RNA nucleic acid molecules are also contemplated.
In some embodiments, the CMV vaccines are attenuated CMV vaccines which are unable or impaired in their ability to replicate or assemble in cells and tissues associated with CMV transmission and disease. In addition, the present disclosure includes embodiments that relate to the unique ability of RhCMV to re-infect sero-positive Rhesus Macaques (or HCMV to re-infect sero-positive humans) in spite of the presence of a significant anti-RhCMV immune response (or anti-HCMV immune response). This inherent property of CMV vectors can be attributed to the extensive repertoire of immune evasion genes encoded by this virus (Hansen, S. G., Powers, C. J., Richards, R., Ventura, A. B., Ford, J. C., Siess, D., Axthelm, M. K., Nelson, J. A., Jarvis, M. A., Picker, L. J., et al. 2010. Evasion of CD8+ T cells is critical for superinfection by cytomegalovirus. Science 328:102-106).
Some embodiments address issues of virus shedding and pathogenesis and relate to two potentially complementary approaches to generate a safe and effective vaccines using the CMV vectors. One approach focuses on development of CMV vectors that are either completely or conditionally spread defective or severely restricted in their replication, but that remain capable of inducing a protective immune response against a heterologous antigen. The second approach focuses on the generation of replication competent CMV vectors that are unable to infect cells, such as epithelial cells, which are a major cell type, along with fibroblasts, in the lung associated with CMV pneumonia. Some embodiments may relate to additional safety features into these vectors, including a block in replication in neural and myeloid cells.
In some embodiments, the HCMV and RhCMV recombinant vectors encode heterologous antigens that may elicit and maintain high level cellular and/or humoral immune responses specific for the encoded antigen.
Further provided are recombinant RhCMV or HCMV vectors including a deletion in one or more RhCMV or HCMV genes that are important for replication. In some embodiments, at least one essential or augmenting gene is UL82, UL94, UL32, UL99, UL115 or UL44, or a homolog thereof. In some embodiments, the recombinant RhCMV or HCMV vectors further include a heterologous antigen, such as a pathogen-specific antigen or a tumor antigen.
For a human CMV (HCMV)/TB vaccine to be safe for all potential subjects in a general population, including individuals with unsuspected immune compromise, the CMV vaccine vector needs to be attenuated without losing the ability to induce protective immunity. CMV can replicate in a wide variety of cells and tissues in the host, including: neurons in the central nervous system (CNS), epithelial cells, hepatocytes, lung and kidney. Myeloid and endothelial cells are considered persistent sites for CMV in the host. During overt CMV disease in immunocompromised individuals, direct infection resulting in destruction of epithelial and endothelial cells in the lung, liver and retina is responsible for disease in these target organs. During congenital infection, direct CMV infection of neuronal cells is believed to account for the associated hearing deficits and mental retardation. Embodiments of the invention relate to modulating the ability of CMV to replicate in these critical cell types in order to increase vector safety without compromising vaccine efficacy, said attenuated viruses and their use as vaccines.
Some embodiments relate to HCMV as a vector for inducing protective immunity to TB, which is based on the highly innovative hypothesis that a high frequency, effector memory-biased T cell response has distinct advantages over conventional vaccine generated memory, combined with the recognition that HCMV provides just such a response. This characteristic of HCMV is unique to this virus, even when compared to other persistent viruses such as herpes simplex virus (HSV) and Epstein-Barr virus (Asanuma, H., Sharp, M., Maecker, H. T., Maino, V. C., and Arvin, A. M. 2000. Frequencies of memory T cells specific for varicella-zoster virus, herpes simplex virus, and cytomegalovirus by intracellular detection of cytokine expression. J Infect Dis 181:859-866; Harari, A., Vallelian, F., Meylan, P. R., and Pantaleo, G. 2005. Functional heterogeneity of memory CD4+ T cell responses in different conditions of antigen exposure and persistence. J Immunol 174:1037-1045; Harari, A., Enders, F. B., Cellerai, C., Bart, P. A., and Pantaleo, G. 2009. Distinct profiles of cytotoxic granules in memory CD8+ T cells correlate with function, differentiation stage, and antigen exposure. J Virol 83:2862-2871; Sylwester, A. W., Mitchell, B. L., Edgar, J. B., Taormina, C., Pelte, C., Ruchti, F., Sleath, P. R., Grabstein, K. H., Hosken, N. A., Kern, F., et al. 2005. Broadly targeted human cytomegalovirus-specific CD4+ and CD8+ T cells dominate the memory compartments of exposed subjects. J Exp Med 202:673-685).
While the HCMV vaccine may be considered safe, concerns still remain regarding both pathogenicity as well as the ability of the virus to spread to unvaccinated sero-negative individuals. The ability to rationally design an HCMV vaccine that is less pathogenic and not shed into the environment is now available with the advent of technological breakthroughs to clone and genetically manipulate CMV. With a long-term goal of generating a CMV vaccine vector encoding TB antigens that is safe and unable to spread to other individuals. Embodiments of this invention relate to the rational design and use of the latest reverse genetic techniques to generate a CMV-based vector that has a restricted tropism for cells involved in shedding as well as an altered ability to replicate in tissues associated with both adult and immunosuppressed populations.
In some embodiments, the recombinant RhCMV or HCMV vaccine vector is a tropism-restricted vector. In some embodiments, the tropism-restrictive vector lacks genes required for optimal growth in certain cell types or contains targets for tissue-specific micro-RNAs in genes essential for viral replication or wherein the tropism-restrictive vector has an epithelial, central nervous system (CNS), or macrophage deficient tropism, or a combination thereof.
Some embodiments relate to alteration of the cell-tropism of the CMV vector so as to prevent infection of specific cell types involved in potential tissue damage and/or shedding into urine or secretions. CMV is capable of infecting a wide variety of cells in the host, including: epithelial cells in gut, kidney, lung and retina, neuronal cells in the CNS, hepatocytes, as well as endothelial cells and myeloid lineage cells that are considered persistent sites of the virus (Dankner, W. M., McCutchan, J. A., Richman, D. D., Hirata, K., and Spector, S. A. 1990. Localization of human cytomegalovirus in peripheral blood leukocytes by in situ hybridization. J Infect Dis 161:31-36; Einhorn, L., and Ost, A. 1984. Cytomegalovirus infection of human blood cells. J Infect Dis 149:207-214; Gnann, J. W., Jr., Ahlmen, J., Svalander, C., Olding, L., Oldstone, M. B., and Nelson, J. A. 1988. Inflammatory cells in transplanted kidneys are infected by human cytomegalovirus. Am J Pathol 132:239-248; Howell, C. L., Miller, M. J., and Martin, W. J. 1979. Comparison of rates of virus isolation from leukocyte populations separated from blood by conventional and Ficoll-Paque/Macrodex methods. J Clin Microbiol 10:533-537; Myerson, D., Hackman, R. C., Nelson, J. A., Ward, D. C., and McDougall, J. K. 1984. Widespread presence of histologically occult cytomegalovirus. Hum Pathol 15:430-439; Schrier, R. D., Nelson, J. A., and Oldstone, M. B. 1985. Detection of human cytomegalovirus in peripheral blood lymphocytes in a natural infection. Science 230:1048-1051; Sinzger, C., Grefte, A., Plachter, B., Gouw, A. S., The, T. H., and Jahn, G. 1995. Fibroblasts, epithelial cells, endothelial cells and smooth muscle cells are major targets of human cytomegalovirus infection in lung and gastrointestinal tissues. J Gen Virol 76:741-750).
HCMV encodes >200 genes and several of the genes that are dispensable for basic virus replication have been identified as tropism determinants that enable the virus to enter and replicate in macrophages, endothelial cells, and epithelial cells. One locus of HCMV genes, UL128-131A, has been shown to be essential for entry into endothelial and epithelial cells (Gema, G., Percivalle, E., Lilleri, D., Lozza, L., Fornara, C., Hahn, G., Baldanti, F., and Revello, M. G. 2005. Dendritic-cell infection by human cytomegalovirus is restricted to strains carrying functional UL131-128 genes and mediates efficient viral antigen presentation to CD8+ T cells. J Gen Virol 86:275-284; Hahn, G., Revello, M. G., Patrone, M., Percivalle, E., Campanini, G., Sarasini, A., Wagner, M., Gallina, A., Milanesi, G., Koszinowski, U., et al. 2004. Human cytomegalovirus UL131-128 genes are indispensable for virus growth in endothelial cells and virus transfer to leukocytes. J Virol 78:10023-10033; Wang, D., and Shenk, T. 2005. Human cytomegalovirus UL131 open reading frame is required for epithelial cell tropism. J Virol 79:10330-10338; Wang, D., and Shenk, T. 2005. Human cytomegalovirus virion protein complex required for epithelial and endothelial cell tropism. Proc Natl Acad Sci USA 102:18153-18158; Ryckman, B. J., Rainish, B. L., Chase, M. C., Borton, J. A., Nelson, J. A., Jarvis, M. A., and Johnson, D. C. 2008. Characterization of the human cytomegalovirus gH/gL/UL128-131 complex that mediates entry into epithelial and endothelial cells. J Virol 82:60-70; Ryckman, B. J., Jarvis, M. A., Drummond, D. D., Nelson, J. A., and Johnson, D. C. 2006. Human cytomegalovirus entry into epithelial and endothelial cells depends on genes UL128 to UL150 and occurs by endocytosis and low-pH fusion. J Virol 80:710-722.).
The RhCMV homologues for HCMV UL128 and 130 are inactivated in the RhCMV strain 68-1. Efficient replication of rhesus cytomegalovirus variants in multiple rhesus and human cell types. Proc Natl Acad Sci USA 105:19950-19955. Interestingly, RhCMV 68-1 still grows in epithelial and endothelial cells (albeit at a reduced rate compared to low passage RhCMV virus with intact UL128/130) (Lilja, A. E., Chang, W. L., Barry, P. A., Becerra, S. P., and Shenk, T. E. 2008. Functional genetic analysis of rhesus cytomegalovirus: Rh-1 is an epithelial cell tropism factor. J Virol 82:2170-2181; Rue, C. A., Jarvis, M. A., Knoche, A. J., Meyers, H. L., DeFilippis, V. R., Hansen, S. G., Wagner, M., Fruh, K., Anders, D. G., Wong, S. W., et al. 2004. A cyclooxygenase-2 homologue encoded by rhesus cytomegalovirus is a determinant for endothelial cell tropism. Journal of Virology 78:12529-12536). Mutational analysis of RhCMV 68-1 has identified 4 other RhCMV genes (Rh01 (HCMV TLR1), Rh159 (HCMV UL148), Rh160 (UL132) and Rh203 (HCMVUS22)) that are also required for epithelial cell tropism (Lilja et al., J Virol, 2008, 82, 2170-2181). Some embodiments relate to the mutation of the remainder of these epithelial cell tropism genes to highly reduce, if not abrogate, the ability of CMV to infect epithelial cells, thereby preventing its ability to be shed into urine or glandular secretions (i.e., saliva and breast milk), yet likely not compromise the ability of a CMV vector to induce a protective immune response to TB.
Moreover, since CMV infection of epithelial cells in the lung and retina results in pneumonia and retinitis, respectively, elimination of all the CMV epithelial cell tropism genes may significantly reduce the resultant vector's pathogenic potential. Aspects of the invention relate to this highly targeted and innovative approach that will significantly enhance both the safety of the RhCMV/HCMV vector for use as a TB vaccine, as well as prevent shedding and the potential spread of the vaccine vector into the unvaccinated population.
Further embodiments relate to exploiting the tissue-specific expression of cellular microRNAs (miRNAs) to attenuate the virus in tissues associated with disease in adult and congenital infection. Endogenous microRNA can be broadly exploited to regulate transgene expression according to tissue, lineage and differentiation state. (Barnes et al., Cell Host Microbe, 2008, 4, 239-248; Lee et al., Clin. Cancer Res., 2009, 15, 5126-5135; Perez et al., Nat. Biotechnol., 2009, 27, 572-576).
Tissue specific expression of miRNAs has been exploited to generate an attenuated polio vaccine through the introduction of multiple miRNA target sequences of miR-124 that is specifically expressed in the CNS into the 3′UTR of the poliovirus genome (Barnes et al., supra). Addition of the miR-124 target sequences to the poliovirus genome was observed to significantly attenuate virus infection in mice. Similarly, multiple target sequences of miR-93 that is ubiquitously expressed in all mammalian but not avian tissues were added to the nucleoprotein gene of influenza resulting in a species-restricted influenza mutant that was able to grow in chicken eggs but not in mice (Perez et al., supra).
Some embodiments relate to this attenuation approach being effective for larger viruses, such as murine CMV (MCMV). Unlike the small RNA viruses, CMV encodes over 200 genes of which approximately 50% are essential and necessary for replication or encode structural proteins of the virus. One of these essential MCMV genes is the immediate early (IE) 3 gene (the mouse correlate of IE2 in HCMV or RhCMV) that encodes a transcriptional regulatory protein necessary for subsequent activation of early and late genes in the virus. Deletion of this gene completely blocks viral replication in cells and mouse tissues (Angulo et al., J. Virol., 2000, 74, 11129-11136). It is described herein that introduction of target sequences of tissue-specific miRNAs into the 3′UTR of this gene would attenuate viral replication in these cells.
In further embodiments, the CMV vector may comprise one or more microRNA recognition elements (MREs). A mature microRNA (interchangeably termed an miRNA or miR) is typically an 18-25 nucleotide non-coding RNA that regulates expression of an mRNA operably linked to an MRE with specificity for the miRNA. An MRE can be any sequence that base pairs with and interacts with the miRNA somewhere on the mRNA transcript. Often, the MRE is present in the 3′ untranslated region (UTR) of the mRNA, but it can also be present in the coding sequence or in the 5′-UTR. MRE's are not necessarily perfect complements to miRNAs, usually having only a few bases of complementarity to the miRNA and often containing one or more mismatches within those bases of complementarity. An MRE, therefore, can be any sequence capable of being bound by an miRNA sufficiently that the translation of a gene to which the MRE is operably linked (such as a CMV gene that is essential or augmenting for growth in vivo) is repressed by an miRNA silencing mechanism such as the RISC.
In some examples, a microRNA recognition element (MRE) is operably linked to a CMV gene that is essential or augmenting for growth in vivo. In other examples, the MRE silences expression in the presence of a miRNA that is expressed in cells of the myeloid lineage. Such miRNA include, but are not limited to, miR-142-3p, miR-223, miR-27a, miR-652, miR-155, miR146a, miR-132, miR-21, or miR-125 (Brown et al., Nat. Biotechnol., 2007, 25, 1457-1467). Myeloid lineage cells have been shown to represent a reservoir of latent virus, and are thought to harbor and disseminate virus throughout the host (Jarvis and Nelson, Front Biosci., 2002, 7, d1575-1582).
Further studies with MCMV (Snyder et al., C. M., Allan, J. E., Bonnett, E. L., Doom, C. M., and Hill, A. B. Cross-presentation of a spread-defective MCMV is sufficient to prime the majority of virus-specific CD8+ T cells. PLoS One 5:e9681) indicate that cross-priming is the primary mechanism by which CMV-encoded proteins prime the immune response, replication in myeloid dendritic cells may have a surprisingly minimal impact on CMV immunogenicity.
Bacterial artificial chromosome (BAC)-based technology is used to generate a recombinant MCMV virus that contained four repeated target sequences (four 21 mers) with exact complementarity to the cellular miRNA, miR-142-3p, within the 3′UTR of the essential viral gene 1E3 (1E3-142). To confirm the extent to which miR-142-3p expression could repress 1E3-142 replication, virus growth assays are performed in the macrophage cell line, IC-21. RT-PCR analysis confirmed that IC-21 cells express high levels of miR-142-3p making the cell line suitable to test the effectiveness of the strategy. Preliminary experiments confirmed the utility of the approach for cell-type specific attenuation of CMV. Although IE3-142 replicated to wild type levels in fibroblasts, growth was completely blocked in IC-21 macrophage cells. A control virus, IE3-015, which contains only vector sequence within the IE3 insertion site, replicates to wild-type levels in IC-21 cells. RT-PCR analysis indicates that IE3 expression was completely abrogated following infection of IC-21 cells, but not following infection of fibroblast cells (lacking miR-142-3p expression) indicating that disruption of IE3 expression is not due to insertion of the target sequence.
Some embodiments relate to strategy to attenuate CMV based on the showing that viruses can be attenuated for tissue-specific growth by using miRNA target sequences and the attenuation of MCMV in myeloid cells through the targeting of cell specific miRNAs to essential viral genes. Since the CNS is a major target for CMV pathogenesis in both congenital and adult disease, HCMV/TB vaccines are generated that contain target sequences of highly conserved miRNAs specifically expressed by neurons fused to essential CMV genes to prevent replication in the CNS. Target sequences of the myeloid miRNA miR-124 to prevent replication and dissemination of the CMV vector in this cell type are also used. Together, these attenuated viruses will provide a further level of safety that will enable the use of this vaccine in all human target populations.
Also disclosed herein are recombinant CMV vectors, such as RhCMV and HCMV vectors, having a deletion in one or more genes that are essential for or augment CMV replication, dissemination or spreading. Thus, these vectors are referred to as “replication-deficient” CMV vectors. As used herein, “replication-deficient” encompasses CMV vectors that are unable to undergo any replication in a host cell, or have a significantly reduced ability to undergo viral replication. In some examples, the replication-deficient CMV vectors are able to replicate, but are unable to disseminate since they are incapable of infection neighboring cells. In some examples, the replication-deficient CMV vectors are able to replicate, but are unable to spread since they are not released from infected hosts.
CMV essential and augmenting genes are well known in the art (see, for example, Dunn et al., Proc. Natl. Acad. Sci. USA, 2003, 100, 14223-14228; and Dong et al., Proc. Natl. Acad. Sci. USA, 2003, 100, 12396-12401), and are described herein. In some embodiments, the recombinant RhCMV or HCMV vector includes a deletion in one gene that is essential for or augments virus replication, dissemination or spreading. In other embodiments, the recombinant RhCMV or HCMV vector includes a deletion in multiple (such as, but not limited to, two, three or four) genes essential for or augmenting CMV replication, dissemination or spreading. The deletion need not be a deletion of the entire open reading frame of the gene, but includes any deletion that eliminates expression of functional protein.
In some embodiments, the recombinant RhCMV or HCMV vaccine vector comprises a deletion in a RhCMV or HCMV gene that is essential for replication within a host, dissemination within a host, or spreading from host to host. In some embodiments, the essential gene is UL82 (encoding pp71), UL94 (encoding the UL94 protein), UL32 (encoding pp150), UL99 (encoding pp28), UL115 (encoding gL) and UL44 (encoding p52), or a homolog thereof.
Replication-deficient RhCMV and HCMV vectors disclosed herein can include a nucleic acid sequence encoding a heterologous antigen, such as a pathogen-specific antigen. As disclosed for other recombinant RhCMV and HCMV vectors described herein, replication-deficient RhCMV and HCMV vectors can be used to elicit an immune response in a subject against the encoded heterologous antigen.
A recombinant RhCMV vector having a deletion in gene UL82 (which encodes the pp71 protein) is severely impaired in its ability to grow in vitro and to spread in vivo, but still elicits a robust T cell immune response against CMV (U.S. Pat. No. 9,249,427). Thus, it is contemplated herein to use such a replication-deficient vector as a vaccine against CMV itself.
In some embodiments, the recombinant RhCMV or HCMV vaccine vector has a deletion in a gene region non-essential for growth in vivo. In some embodiments, the gene region is selected from the group consisting of the RL11 family, the pp65 family, the US12 family, and the US28 family. In some embodiments, the RhCMV gene region is selected from the group consisting of Rh13-Rh29, Rh111-Rh112, Rh191-Rh202, and Rh214-Rh220. In some embodiments, the RhCMV gene region is selected from the group consisting of Rh13.1, Rh19, Rh20, Rh23, Rh24, Rh112, Rh190, Rh192, Rh196, Rh198, Rh199, Rh200, Rh201, Rh202, and Rh220. In some embodiments, the HCMV gene region is selected from the group consisting of RL11, UL6, UL7, UL9, UL11, UL83 (pp65), US12, US13, US14, US17, US18, US19, US20, US21, and UL28.
In some embodiments, the recombinant RhCMV or HCMV vector comprises a deletion in a RhCMV or HCMV gene that is essential for or augments replication. CMV essential genes and augmenting have been well described in the art (see, for example, Dunn et al., supra; and Dong et al., supra). Essential CMV genes include, but are not limited to, UL32, UL34, UL37, UL44, UL46, UL48, UL48.5, UL49, UL50, UL51 UL52, UL53, UL54, UL55, UL56, UL57, UL60, UL61, UL70, UL71, UL73, UL75, UL76, UL77, UL79, UL80, UL82, UL84, UL85, UL86, UL87, UL89, UL90, UL91, UL92, UL93, UL94, UL95, UL96, UL98, UL99, UL100, UL102, UL104, UL105, UL115 and UL122. In some embodiments, the CMV essential or augmenting gene is UL82, UL94, UL32, UL99, UL115 or UL44, or a homolog thereof (i.e., the homologous gene in RhCMV). Other essential or augmenting genes are known in the art and are described herein. In particular examples, the essential gene is UL82, or a homolog thereof. In some embodiments, the recombinant RhCMV and HCMV vectors do not include a heterologous antigen. In other embodiments, the recombinant RhCMV or HCMV vector having a deletion in an essential or augmenting gene includes a nucleic acid sequence encoding a heterologous antigen, such as a pathogen-specific antigen or a tumor antigen. Compositions comprising recombinant RhCMV or HCMV vectors and a pharmaceutically acceptable carrier also are provided. Such vectors and compositions can be used, for example, in a method of treating a subject with an infectious disease, or at risk of becoming infected with an infectious disease. CMV vectors having a deletion of at least one important gene are generally attenuated and thus can be used as vaccines for the treatment or prevention of CMV (in which case, the recombinant vector does not encode a heterologous antigen).
In some embodiments, the recombinant RhCMV or HCMV vectors comprise a suicide or safety means to prevent further replication of the virus. For example, the recombinant CMV vectors can include LoxP sites flanking an essential gene or region of the RhCMV or HCMV genome (essential CMV genes are listed above and are known in the art), as well as the coding sequence for Cre-recombinase. Cre-recombinase is generally under the control of an inducible promoter to regulate expression of Cre, thereby controlling removal of the essential gene and inhibition of viral replication. In particular examples, Cre is a Tet-regulated Cre and expression of Cre is controlled by the presence of Dox.
The present disclosure also relates to a method of a CMV vector capable of repeatedly infecting an organism which may comprise (a) constructing a vector containing and over-expressing at least one cytomegalovirus (CMV) glycoprotein, wherein the glycoprotein is US2, US3, US6 or US11, and (b) administering the vector repeatedly into the animal or human. Where superinfectivity is desired, any CMV vector, may express one or more of the HCMV glycoproteins US2, US3, US6 and US11 (or the RhCMV homologues Rh182, Rh184, Rh185, Rh189).
In some embodiments, the recombinant RhCMV or HCMV vaccine vector further comprises a second nucleic acid sequence encoding US2, US3, or US6, or a homolog thereof, wherein the vector does not encode a functional US11. In some embodiments, the second nucleic acid sequence encodes US2, US3, and US6. In some embodiments, the nucleic acid encoding a US11 open reading frame is deleted. In some embodiments, the recombinant RhCMV or HCMV vaccine vector further comprises a third nucleic acid sequence encoding US11, and wherein the nucleic acid sequence encoding US11 comprises a point mutation, a frameshift mutation, and/or a deletion of one or more nucleotides of the nucleic acid sequence encoding US11.
In some embodiments, the glycoproteins within the US2 to US11 region of RhCMV or HCMV are deleted from the vector. In some embodiments, the recombinant RhCMV or HCMV vaccine vector lacks the transactivator pp71. In some embodiments, the recombinant RhCMV or HCMV vaccine vector lacks the tegument protein pp65.
In some embodiments, the recombinant RhCMV or HCMV vaccine vector further comprises a nucleic acid sequence that encodes UL128 or an ortholog thereof, and another nucleic acid sequence that encodes UL131 or an ortholog thereof, wherein the vector does not express an active UL130 protein.
In some embodiments, the recombinant RhCMV or HCMV vaccine vector further comprises a nucleic acid sequence that encodes UL130 or an ortholog thereof, and another nucleic acid sequence that encodes UL131 or an ortholog thereof, wherein the vector does not express an active UL128 protein.
In some embodiments, the recombinant RhCMV or HCMV vaccine vector comprises a mutation in UL128 or UL130 selected from a point mutation, a frameshift mutation, and a deletion of all or less than all of UL128 or UL130.
In some embodiments, the recombinant RhCMV or HCMV vaccine vector further comprises an antisense sequence or an RNAi sequence that inhibits the expression of UL128 or UL130 or both.
In some embodiments, the recombinant RhCMV or HCMV vaccine vector comprises a deletion or modification of US2, US3, US4, US5, US6, US11, or UL97, or a homolog thereof.
In some embodiments, the recombinant RhCMV or HCMV vaccine vector comprises a deletion of Rh158-166 or a homolog thereof
In some embodiments where repeated infection of a CMV vector is desired, the CMV vector may express one or more of the glycoproteins US2, US3, US6 and US11. In a particularly advantageous embodiment, the vector expresses glycoproteins US2, US3, US6 and US11. More advantageously, the vector contains and expresses all of the glycoproteins within the US2 to US11 region of CMV. In an advantageous embodiment, the one or more of the glycoproteins US2, US3, US6 and US11 may include, but not limited to, the glycoproteins of U.S. Pat. Nos. 7,892,564; 7,749,745; 7,364,893; 6,953,661; 6,913,751; 6,740,324; 6,613,892; 6,410,033; 6,140,114; 6,103,531; 6,033,671; 5,908,780; 5,906,935; 5,874,279; 5,853,733; 5,846,806; 5,843,458; 5,837,532; 5,804,372; 5,753,476; 5,741,696; 5,731,188; 5,720,957; 5,676,952; 5,599,544; 5,593,873 and 5,334,498.
Disclosed herein are human or animal CMV vectors comprising a nucleic acid sequence that encodes a heterologous protein antigen and a nucleic acid sequence that encodes an active UL131 protein. In one example, the CMV vector comprises a nucleic acid sequence that expresses an active UL128 protein but does not express an active UL130 protein. In another example, the CMV vector encodes an active UL130 protein but does not express an active UL128 protein.
In some examples, the CMV vector does not express an active UL128 or UL130 protein due to the presence of a deleterious mutation in the nucleic acid sequence encoding UL128 or UL130 or their orthologous genes in animal CMVs. The mutation may be any deleterious mutation that results in a lack of expression of active UL128 or UL130 protein. Such mutations can include point mutations, frameshift mutations, deletions of less than all of the sequence that encodes the protein (truncation mutations), or deletions of all of the nucleic acid sequence that encodes the protein, or any other mutations.
In further examples, the CMV vector does not express an active UL128 or UL130 protein due to the presence of a nucleic acid sequence in the vector that comprises an antisense or RNAi sequence (siRNA or miRNA) that inhibits the expression of the UL128 or UL130 protein.
Also disclosed herein are methods of generating CD8+ T cell responses to heterologous antigens in a subject. The methods involve administering an effective amount of a CMV vector to the subject. The CMV vector is characterized by having a nucleic acid sequence that encodes a heterologous antigen and a nucleic acid sequence that encodes an active UL131 protein. The CMV vector is further characterized by not encoding an active UL128 protein or an active UL130 protein or neither an active UL128 or active UL130 protein. The CD8+ T cell response is further characterized by having at least 10% of the CD8+ T cells directed against epitopes presented by MHC class II. In further examples, at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, or more than 60% of the CD8+ T cells are directed against epitopes presented by MHC class II.
In further examples, the methods involve administering an effective amount of a second CMV vector, the second CMV vector comprising a nucleic acid sequence that encodes a heterologous antigen to the subject. This second vector can be any CMV vector, including a CMV vector with an active UL128 and an active UL130 protein. The second CMV vector may comprise additional deletions known in the art to provide different immune responses such as a US11 deletion or any other deletion. The second heterologous antigen can be any heterologous antigen, including a heterologous antigen identical to the heterologous antigen in the first CMV vector. The second CMV vector can be administered at any time relative to the administration of the first CMV vector including before, concurrently with, or after the administration of the first CMV vector. This includes administration of the second vector any number of months, days, hours, minutes or seconds before or after the first vector. In preferred embodiments of the present invention viral vectors are used. Advantageously, the vector is a CMV vector, lacking at least the glycoprotein UL128 or a CMV vector lacking at least the glycoprotein UL130. Each CMV vector also expresses the glycoprotein UL131.
Suitable dosages of the CMV vectors in the immunogenic compositions can be readily determined by those of skill in the art. For example, the dosage of the CMV vectors can vary depending on the route of administration and the size of the subject. Suitable doses can be determined by those of skill in the art, for example by measuring the immune response of a subject, such as a laboratory animal, using conventional immunological techniques, and adjusting the dosages as appropriate. Such techniques for measuring the immune response of the subject include but are not limited to, chromium release assays, tetramer binding assays, IFN-.gamma. ELISPOT assays, IL-2 ELISPOT assays, intracellular cytokine assays, and other immunological detection assays, e.g., as detailed in the text “Antibodies: A Laboratory Manual” by Ed Harlow and David Lane.
In some embodiments, the recombinant RhCMV vaccine vector is Rh68-1 or Rh68-1.2. During in vitro culture on fibroblasts, the Rh68-1 CMV vector lost the ability to express gene products from the Rh13, Rh60, Rh157.5, and Rh157.6 open reading frames. The HCMV orthologs of these genes are RL11, UL36, UL128, and UL130, respectively. The Rh68-1.2 vector had expression of Rh60, Rh157.5, and Rh157.6 restored through recombinant DNA techniques (Lilja and Shenk, Proc. Natl. Acad. Sci. USA, 2008, 105, 19950-19955). The Rh68-1 CMV vector, but not the Rh68-1.2 CMV vector, primes surprisingly high number of CD8+ T cells restricted by MHC-E.
In some embodiments, the CMV vectors can comprise regulatory elements for gene expression of the coding sequences of the nucleic acid. The regulatory elements can be a promoter, an enhancer an initiation codon, a stop codon, a polyadenylation signal, additional restriction enzyme sites, multiple cloning sites, or other coding segments, and the like. In some embodiments, the CMV vector can comprise heterologous nucleic acid encoding an Mtb antigen and can further comprise an initiation codon, which is upstream of the antigen coding sequence, and a stop codon, which is downstream of the antigen coding sequence. The initiation and termination codon are in frame with the antigen coding sequence.
In some embodiments, expression of the Mtb antigen is driven by an antigen-coding sequence in operable association with a promoter selected from the group consisting of a constitutive CMV promoter, an immediate early CMV promoter, an early CMV promoter, and a late CMV promoter. In some embodiments, the promoter is selected from the group consisting of EF1-alpha, UL82, MIE, pp65, and gH.
The CMV vector can also comprise a polyadenylation signal, which can be downstream of the antigen coding sequence. The polyadenylation signal can be a SV40 polyadenylation signal, LTR polyadenylation signal, CMV polyadeylation signal, bovine growth hormone (bGH) polyadenylation signal, human growth hormone (hGH) polyadenylation signal, or human 0-globin polyadenylation signal. The SV40 polyadenylation signal can be a polyadenylation signal from a pCEP4 vector (Invitrogen, San Diego, CA).
The CMV vector can also comprise an enhancer. In some embodiments, the enhancer can be necessary for DNA expression. The enhancer can be human actin, human myosin, human hemoglobin, human muscle creatine or a viral enhancer such as one from CMV, RSV or EBV. Polynucleotide function enhances are described in U.S. Pat. Nos. 5,593,972, 5,962,428, and WO94/016737, the contents of each are incorporated herein by reference.
The CMV vector can also comprise a mammalian origin of replication to maintain the vector extrachromosomally and produce multiple copies of the vector in a cell. The CMV vector can comprise the Epstein Barr virus origin of replication and nuclear antigen EBNA-1 coding region, which can produce high copy episomal replication without integration. The CMV vector can contain certain elements of the pVAX1 or a pVax1 variant. The variant pVax1 plasmid is a 2998 basepair variant of the backbone vector plasmid pVAX1 (Invitrogen, Carlsbad CA). The CMV promoter is located at bases 137-724. The T7 promoter/priming site is at bases 664-683. Multiple cloning sites are at bases 696-811. Bovine GH polyadenylation signal is at bases 829-1053. The Kanamycin resistance gene is at bases 1226-2020. The pUC origin is at bases 2320-2993.
The CMV vector can also comprise a regulatory sequence, which can be well suited for gene expression in a mammalian or human cell into which the vector is administered. The consensus coding sequence can comprise a codon, which can allow more efficient transcription of the coding sequence in the host cell.
The present disclosure also provides host cells comprising any of the nucleic acid molecules or CMV vectors disclosed herein. The host cells can be used, for example, to express the Mtb antigens, or fragments of thereof. The Mtb antigens, or fragments thereof, can also be expressed in cells in vivo. The host cell that is transformed (for example, transfected) to produce the Mtb antigens, or fragments of thereof can be an immortalised mammalian cell line, such as those of lymphoid origin (for example, a myeloma, hybridoma, trioma or quadroma cell line). The host cell can also include normal lymphoid cells, such as B-cells, that have been immortalized by transformation with a virus (for example, the Epstein-Barr virus).
In some embodiments, the host cells include, but are not limited to: bacterial cells, such as E. coli, Caulobacter crescentus, Streptomyces species, and Salmonella typhimurium; yeast cells, such as Saccharomyces cerevisiae, Schizosaccharomyces pombe, Pichia pastoris, Pichia methanolica; insect cell lines, such as those from Spodoptera frugiperda (for example, Sf9 and Sf21 cell lines, and ExpresSF™ cells (Protein Sciences Corp., Meriden, CT, USA)), Drosophila S2 cells, and Trichoplusia in High Five® Cells (Invitrogen, Carlsbad, CA, USA); and mammalian cells, such as COS 1 and COS7 cells, Chinese hamster ovary (CHO) cells, NSO myeloma cells, NIH 3T3 cells, 293 cells, Proce1192S, perC6, HEPG2 cells, HeLa cells, L cells, HeLa, MDCK, HEK293, WI38, murine ES cell lines (for example, from strains 129/SV, C57/BL6, DBA-1, 129/SVJ), K562, Jurkat cells, and BW5147. Other useful mammalian cell lines are well known and readily available from the American Type Culture Collection (“ATCC”) (Manassas, VA, USA) and the National Institute of General Medical Sciences (NIGMS) Human Genetic Cell Repository at the Coriell Cell Repositories (Camden, NJ, USA). In some embodiments, the cell is a recombinant BCG. These cell types are only representative and are not meant to be an exhaustive list.
Among other considerations, some of which are described above, a host cell strain may be chosen for its ability to process the expressed Mtb antigens, or fragment thereof, in the desired fashion. Post-translational modifications of the polypeptide include, but are not limited to, glycosylation, acetylation, carboxylation, phosphorylation, lipidation, and acylation, and it is an aspect of the present disclosure to provide Mtb antigens thereof with one or more of these post-translational modifications.
In some embodiments, the recombinant BCG has been genetically engineered to express a functional endosomalytic protein that is bioactive at pH values near neutrality (e.g. about pH 6-8 or about 6.5 to 7.5). The endosomalytic protein is active within Mycobacteria-containing endosomes, which typically have an internal pH near neutrality. The activity of the endosomalytic protein produced by the rBCG results in disruption of the endosome, permitting the rBCG to escape from the endosome and into the cytoplasm of the cell. In some embodiments, the endosomalytic protein that is introduced into the rBCG by genetic engineering is Perfringolysin O (PfoA) from Clostridium perfringens or a mutant thereof, such as PfoAG137Q, as described in WO 2007/058663, which is incorporated herein by reference in its entirety.
In some embodiments, the Mycobacteria are attenuated, as exemplified by BCG. However, those of skill in the art will recognize that other attenuated and nonattenuated Mycobacteria exist which would also be suitable for use herein. Examples of additional types of Mycobacteria include, but are not limited to, M. tuberculosis strain CDCl551, M. tuberculosis strain Beijing, M. tuberculosis strain H37Ra (ATCC #:25177), M. tuberculosis strain H37Rv (ATCC #:25618), M. bovis (ATCC #:19211 and 27291), M. fortuitum (ATCC #:15073), M. smegmatis (ATCC #:12051 and 12549), M. intracellulare (ATCC #:35772 and 13209), M. kansasii (ATCC #:21982 and 35775)M. avium (ATCC #:19421 and 25291), M. gallinarum (ATCC #: 19711), M vaccae (ATCC #: 15483 and 23024), M. leprae (ATCC #:), M. marinarum (ATCC #:11566 and 11567), and M. microtti (ATCC #:11152).
Examples of attenuated Mycobacterium strains include, but are not restricted To, M. tuberculosis pantothenate auxotroph strain, M. tuberculosis rpoV mutant strain, M. tuberculosis leucine auxotroph strain, BCG Danish strain (ATCC #35733), BCG Japanese strain (ATCC #35737), BCG Chicago strain (ATCC #27289), BCG Copenhagen strain (ATCC #: 27290), BCG Pasteur strain (ATCC #: 35734), BCG Glaxo strain (ATCC #: 35741), BCG Connaught strain (ATCC #35745), BCG Montreal (ATCC #35746), BCG1331 strain, BCG Tokyo strain, BCG Moreau strain, BCG-Pasteur Aeras, and BCG Moscow strain.
The present disclosure also provides pharmaceutical compositions comprising any one or more of the recombinant RhCMV or HCMV vaccine vectors described herein and a pharmaceutically acceptable carrier.
In some embodiments, the Mtb antigen, or fragment thereof, is labeled with a detectable marker. Detectable markers include, but are not limited to, radioactive isotopes (such as P32 and S35), enzymes (such as horseradish peroxidase, chloramphenicol acetyltransferase (CAT), β-galactosidase (β-gal), and the like), fluorochromes, chromophores, colloidal gold, dyes, and biotin. The labeled Mtb antigens, or fragments thereof, can be used to carry out diagnostic procedures in a variety of cell or tissue types. For imaging procedures, in vitro or in vivo, the Mtb antigens can be labeled with additional agents, such as NMR contrasting agents, X-ray contrasting agents, or quantum dots. Methods for attaching a detectable agent to polypeptides are known in the art. The Mtb antigens can also be attached to an insoluble support (such as a bead, a glass or plastic slide, or the like).
In some embodiments, the Mtb antigens, or fragment thereof, can be conjugated to a therapeutic agent including, but not limited to, radioisotopes (such as 111In or 90Y), toxins (such as tetanus toxoid or ricin), toxoids, and chemotherapeutic agents.
In some embodiments, the Mtb antigens, or fragments thereof, can be conjugated to an imaging agent. Imaging agents include, for example, a labeling moiety (such as biotin, fluorescent moieties, radioactive moieties, histidine tag or other peptide tags) for easy isolation or detection.
The present disclosure also provides compositions comprising any one or more of the fusion proteins, Mtb antigens, nucleic acid molecules encoding Mtb antigens, including fusion proteins thereof, cells, and/or CMV vectors and a pharmaceutically acceptable carrier useful in, for example, vaccines.
In some embodiments, liquid formulations of a pharmaceutical composition for oral administration prepared in water or other aqueous vehicles can contain various suspending agents such as methylcellulose, alginates, tragacanth, pectin, kelgin, carrageenan, acacia, polyvinylpyrrolidone, and polyvinyl alcohol. Liquid formulations of pharmaceutical compositions can also include solutions, emulsions, syrups and elixirs containing, together with the active compound(s), wetting agents, sweeteners, and coloring and flavoring agents. Various liquid and powder formulations of the pharmaceutical compositions can be prepared by conventional methods for inhalation into the lungs of the mammal to be treated.
In some embodiments, liquid formulations of a pharmaceutical composition for injection can comprise various carriers such as vegetable oils, dimethylacetamide, dimethylformamide, ethyl lactate, ethyl carbonate, isopropyl myristate, ethanol, polyols such as, for example, glycerol, propylene glycol, liquid polyethylene glycol, and the like. In some embodiments, the composition includes a citrate/sucrose/tween carrier. For intravenous injections, water soluble versions of the compositions can be administered by the drip method, whereby a pharmaceutical formulation containing the antifungal agent and a physiologically acceptable excipient is infused. Physiologically acceptable excipients can include, for example, 5% dextrose, 0.9% saline, Ringer's solution or other suitable excipients. A suitable insoluble form of the composition can be prepared and administered as a suspension in an aqueous base or a pharmaceutically acceptable oil base, such as an ester of a long chain fatty acid such as, for example, ethyl oleate.
The compositions can be, for example, injectable solutions, aqueous suspensions or solutions, non-aqueous suspensions or solutions, solid and liquid oral formulations, salves, gels, ointments, intradermal patches, creams, aerosols, lotions, tablets, capsules, sustained release formulations, and the like. In some embodiments, for topical applications, the pharmaceutical compositions can be formulated in a suitable ointment. In some embodiments, a topical semi-solid ointment formulation typically comprises a concentration of the active ingredient from about 1 to 20%, or from 5 to 10%, in a carrier, such as a pharmaceutical cream base. Some examples of formulations of a composition for topical use include, but are not limited to, drops, tinctures, lotions, creams, solutions, and ointments containing the active ingredient and various supports and vehicles.
Typically, compositions are prepared as injectables, either as liquid solutions or suspensions; solid forms suitable for solution in, or suspension in, liquid vehicles prior to injection can also be prepared. The preparation also can be emulsified or encapsulated in liposomes or microparticles such as polylactide, polyglycolide, or copolymer for enhanced adjuvant effect (see Langer, Science, 1990, 249, 1527 and Hanes, Advanced Drug Delivery Reviews, 1997, 28, 97). A sterile injectable preparation such as, for example, a sterile injectable aqueous or oleaginous suspension can also be prepared. This suspension may be formulated according to techniques known in the art using suitable dispersing, wetting, and suspending agents. In some embodiments, the pharmaceutical composition can be delivered in a microencapsulation device so as to reduce or prevent a host immune response against the protein.
A suitable dose is an amount of a compound that, when administered as described above, is capable of promoting an anti-TB immune response, and is preferably at least 10-50% above the basal (i.e., untreated) level. Such response can be monitored, for example, by measuring the anti-T cell responses in a patient. Such vaccines should also be capable of causing an immune response that leads to an improved clinical outcome (e.g., more frequent remissions, complete or partial or longer disease-free survival) in vaccinated patients as compared to non-vaccinated patients. In general, for pharmaceutical compositions and vaccines comprising one or more polypeptides, the amount of each polypeptide sought in a dose ranges from about 25 mcg to 5 mg per kg of host. Suitable dose sizes will vary with the size of the patient, but will typically range from about 0.1 mL to about 5 mL.
In general, an appropriate dosage and treatment regimen provides the active compound(s) in an amount sufficient to provide therapeutic and/or prophylactic benefit. Such a response can be monitored by establishing an improved clinical outcome (e.g. more frequent remissions, complete or partial, or longer disease-free survival) in treated patients as compared to non-treated patients. Increases in preexisting immune responses to a TB protein may correlate with an improved clinical outcome. Such immune responses may generally be evaluated using standard proliferation, cytotoxicity or cytokine assays, which may be performed using samples obtained from a patient before and after treatment.
In some embodiments, the compositions comprise about 1 nanogram to about 10 mg of nucleic acid. In some embodiments, the compositions comprise: 1) at least 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95 or 100 nanograms, or at least 1, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 105, 110, 115, 120, 125, 130, 135, 140, 145, 150, 155, 160, 165, 170, 175, 180, 185, 190, 195, 200, 205, 210, 215, 220, 225, 230, 235, 240, 245, 250, 255, 260, 265, 270, 275, 280, 285, 290, 295, 300, 305, 310, 315, 320, 325, 330, 335, 340, 345, 350, 355, 360, 365, 370, 375, 380, 385, 390, 395, 400, 405, 410, 415, 420, 425, 430, 435, 440, 445, 450, 455, 460, 465, 470, 475, 480, 485, 490, 495, 500, 605, 610, 615, 620, 625, 630, 635, 640, 645, 650, 655, 660, 665, 670, 675, 680, 685, 690, 695, 700, 705, 710, 715, 720, 725, 730, 735, 740, 745, 750, 755, 760, 765, 770, 775, 780, 785, 790, 795, 800, 805, 810, 815, 820, 825, 830, 835, 840, 845, 850, 855, 860, 865, 870, 875, 880, 885, 890, 895, 900, 905, 910, 915, 920, 925, 930, 935, 940, 945, 950, 955, 960, 965, 970, 975, 980, 985, 990, 995 or 1000 micrograms, or at least 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5 or 10 mg or more; and 2) up to and including 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95 or 100 nanograms, or up to and including 1, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 105, 110, 115, 120, 125, 130, 135, 140, 145, 150, 155, 160, 165, 170, 175, 180, 185, 190, 195, 200, 205, 210, 215, 220, 225, 230, 235, 240, 245, 250, 255, 260, 265, 270, 275, 280, 285, 290, 295, 300, 305, 310, 315, 320, 325, 330, 335, 340, 345, 350, 355, 360, 365, 370, 375, 380, 385, 390, 395, 400, 405, 410, 415, 420, 425, 430, 435, 440, 445, 450, 455, 460, 465, 470, 475, 480, 485, 490, 495, 500, 605, 610, 615, 620, 625, 630, 635, 640, 645, 650, 655, 660, 665, 670, 675, 680, 685, 690, 695, 700, 705, 710, 715, 720, 725, 730, 735, 740, 745, 750, 755, 760, 765, 770, 775, 780, 785, 790, 795, 800, 805, 810, 815, 820, 825, 830, 835, 840, 845, 850, 855, 860, 865, 870, 875, 880, 885, 890, 895, 900, 905, 910, 915, 920, 925, 930, 935, 940, 945, 950, 955, 960, 965, 970, 975, 980, 985, 990, 995, or 1000 micrograms, or up to and including 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5 or 10 mg.
In some embodiments, the compositions comprise about 5 nanograms to about 10 mg of nucleic acid molecule. In some embodiments, the compositions comprise about 25 nanograms to about 5 mg of nucleic acid molecule. In some embodiments, the compositions contain about 50 nanograms to about 1 mg of nucleic acid molecule. In some embodiments, the compositions contain about 0.1 to about 500 micrograms of nucleic acid molecule. In some embodiments, the compositions contain about 1 to about 350 micrograms of nucleic acid molecule. In some embodiments, the compositions contain about 5 to about 250 micrograms of nucleic acid molecule. In some embodiments, the compositions contain about to about 200 micrograms of nucleic acid molecule. In some embodiments, the compositions contain about 15 to about 150 micrograms of nucleic acid molecule. In some embodiments, the compositions contain about 20 to about 100 micrograms of nucleic acid molecule. In some embodiments, the compositions contain about 25 to about 75 micrograms of nucleic acid molecule. In some embodiments, the compositions contain about 30 to about 50 micrograms of nucleic acid molecule. In some embodiments, the compositions contain about 35 to about 40 micrograms of nucleic acid molecule. In some embodiments, the compositions contain about 100 to about 200 micrograms of nucleic acid molecule. In some embodiments, the compositions comprise about 10 to about 100 micrograms of nucleic acid molecule. In some embodiments, the compositions comprise about 20 to about 80 micrograms of nucleic acid molecule. In some embodiments, the compositions comprise about 25 to about 60 micrograms of nucleic acid molecule. In some embodiments, the compositions comprise about 30 nanograms to about 50 micrograms of nucleic acid molecule. In some embodiments, the compositions comprise about 35 nanograms to about 45 micrograms of nucleic acid molecule. In some embodiments, the compositions contain about 0.1 to about 500 micrograms of nucleic acid molecule. In some embodiments, the compositions contain about 1 to about 350 micrograms of nucleic acid molecule. In some embodiments, the compositions contain about 25 to about 250 micrograms of nucleic acid molecule. In some embodiments, the compositions contain about 100 to about 200 micrograms of nucleic acid molecule.
The compositions can be formulated according to the mode of administration to be used. In cases where compositions are injectable pharmaceutical compositions, they are sterile, pyrogen free and particulate free. An isotonic formulation can be used. Generally, additives for isotonicity can include sodium chloride, dextrose, mannitol, sorbitol and lactose. In some cases, isotonic solutions such as phosphate buffered saline are suitable. Stabilizers include gelatin and albumin. In some embodiments, a vasoconstriction agent is added to the formulation.
The compositions can further comprise a pharmaceutically acceptable excipient. The pharmaceutically acceptable excipient can be functional molecules as vehicles, adjuvants, carriers, or diluents. The pharmaceutically acceptable excipient can be a transfection facilitating agent, which can include surface active agents, such as immune-stimulating complexes (ISCOMS), Freund's incomplete adjuvant, LPS analog including monophosphoryl lipid A, muramyl peptides, quinone analogs, vesicles such as squalene and squalane, hyaluronic acid, lipids, liposomes, calcium ions, viral proteins, polyanions, polycations, or nanoparticles, or other known transfection facilitating agents. The transfection facilitating agent is a polyanion, polycation, including poly-L-glutamate (LGS), or lipid. The transfection facilitating agent is poly-L-glutamate, and more suitably, the poly-L-glutamate is present in the composition at a concentration less than 6 mg/ml. The transfection facilitating agent can also include surface active agents such as immune-stimulating complexes (ISCOMS), Freunds incomplete adjuvant, LPS analog including monophosphoryl lipid A, muramyl peptides, quinone analogs and vesicles such as squalene and squalane, and hyaluronic acid can also be used administered in conjunction with the genetic construct. In some embodiments, the plasmid compositions can also include a transfection facilitating agent such as lipids, liposomes, including lecithin liposomes or other liposomes known in the art, as a DNA-liposome mixture (see for example WO9324640), calcium ions, viral proteins, polyanions, polycations, or nanoparticles, or other known transfection facilitating agents. In some embodiments, the transfection facilitating agent is a polyanion, polycation, including poly-L-glutamate (LGS), or lipid. Concentration of the transfection agent in the composition is less than 4 mg/ml, less than 2 mg/ml, less than 1 mg/ml, less than 0.750 mg/ml, less than 0.500 mg/ml, less than 0.250 mg/ml, less than 0.100 mg/ml, less than 0.050 mg/ml, or less than 0.010 mg/ml.
The pharmaceutically acceptable excipient may be an adjuvant. The adjuvant may be other genes that are expressed in alternative plasmid or are delivered as proteins in combination with the plasmid above. The adjuvant may be selected from the group consisting of: α-interferon (IFN-α), β-interferon (IFN-β), γ-interferon, platelet derived growth factor (PDGF), TNFα, TNFβ, GM-CSF, epidermal growth factor (EGF), cutaneous T cell-attracting chemokine (CTACK), epithelial thymus-expressed chemokine (TECK), mucosae-associated epithelial chemokine (MEC), IL-12, IL-15, MHC, CD80,CD86 including IL-15 having the signal sequence deleted and optionally including the signal peptide from IgE. The adjuvant may be IL-12, IL-15, IL-28, CTACK, TECK, platelet derived growth factor (PDGF), TNFα, TNFβ, GM-CSF, epidermal growth factor (EGF), IL-1, IL-2, IL-4, IL-5, IL-6, IL-10, IL-12, IL-18, or a combination thereof.
Other genes which may be useful adjuvants include those encoding: MCP-1, MIP-la, MIP-1p, IL-8, L-selectin, P-selectin, E-selectin, CD34, GlyCAM-1, MadCAM-1, LFA-1, VLA-1, Mac-1, p150.95, PECAM, ICAM-1, ICAM-2, ICAM-3, CD2, LFA-3, M-CSF, G-CSF, IL-4, mutant forms of IL-18, CD40, CD40L, vascular growth factor, fibroblast growth factor, IL-7, nerve growth factor, vascular endothelial growth factor, Fas, TNF receptor, Flt, Apo-1, p55, WSL-1, DR3, TRAMP, Apo-3, AIR, LARD, NGRF, DR4, DR5, KILLER, TRAIL-R2, TRICK2, DR6, Caspase ICE, Fos, c-jun, Sp-1, Ap-1, Ap-2, p38, p65Rel, MyD88, IRAK, TRAF6, IkB, Inactive NIK, SAP K, SAP-1, JNK, interferon response genes, NFkB, Bax, TRAIL, TRAILrec, TRAILrecDRC5, TRAIL-R3, TRAIL-R4, RANK, RANK LIGAND, Ox40, Ox40 LIGAND, NKG2D, MICA, MICB, NKG2A, NKG2B, NKG2C, NKG2E, NKG2F, TAP1, TAP2 and functional fragments thereof.
The plasmid compositions can further comprise a genetic vaccine facilitator agent as described in U.S. Ser. No. 021,579 filed Apr. 1, 1994, which is fully incorporated by reference.
The present disclosure also provides kits comprising any of the Mtb antigens, fragments thereof, fusion proteins, nucleic acid molecules, CMV vectors, or cells, described herein. The kit can include, for example, container(s), package(s) or dispenser(s) along with labels and instructions for administration or use.
Vaccine CMV vectors and pharmaceutical compositions may be presented in unit-dose or multi-dose containers, such as sealed ampoules or vials. Such containers can be hermetically sealed to preserve sterility of the formulation until use. In general, formulations may be stored as suspensions, solutions or emulsions in oily or aqueous vehicles. Alternatively, a vaccine or pharmaceutical composition may be stored in a freeze-dried condition requiring only the addition of a sterile liquid carrier immediately prior to use.
The present disclosure also provides methods for treatment or prevention of tuberculosis comprising administering to a subject in need thereof at least one recombinant RhCMV or HCMV vaccine vector as described herein. In some embodiments, the methods further comprise re-administering to the subject at least one recombinant RhCMV or HCMV vaccine vector described herein. In some embodiments, the recombinant RhCMV or HCMV vaccine vector of the re-administration is different than the recombinant RhCMV or HCMV vaccine vector of the initial administration.
The present disclosure also provides methods for eliciting an immune response to a Mtb antigen comprising administering to a subject in need thereof at least one recombinant RhCMV or HCMV vaccine vector as described herein.
The present disclosure also provides methods for eliciting a CD8+ or CD4+ T cell response to a Mtb antigen comprising administering to a subject in need thereof at least one recombinant RhCMV or HCMV vaccine vector as described herein.
In some embodiments, the recombinant RhCMV or HCMV vaccine vector is administered to the subject intravenously, intramuscularly, intraperitoneally, intranasally, or orally. In some embodiments, the subject is a human.
In some embodiments, any of the Mtb antigens, constructs, vectors, or cells described herein, or compositions comprising the same, can be administered to a mammal as an aerosol. In some embodiments, the aerosol inocula comprises saline. Conventional aerosol delivery devices include, but are not limited to, a pressurized metered dose inhaler (pMDI) and a dry power inhaler (DPI), both of which deliver a dry powder formulation, and nebulizers such as the PARI eFlow device, which delivers an aqueous dose as a fine mist. In some embodiments, the aerosol delivery device is a Pari eFlow portable electronic aerosol delivery platform attached to a delivery mask. In some embodiments, the average particle size is from about 1 μm to about 10 μm, from about 1 μm to about 5 μm, from about 3 μm to about 5 μm, from about 4 μm to about 5 μm, or from about 3.9 μm to about 4.9 μm. In some embodiments, the aerosol is in a volume from about 0.1 ml to about 5 ml, from about 0.1 ml to about 2 ml, from about 0.1 ml to about 1.5 ml, from about 0.5 ml to about 1.5 ml, from about 0.5 ml to about 1.2 ml, from about 0.7 ml to about 1.2 ml, or about 1 ml.
Effective doses of the compositions of the present disclosure, for the treatment of a condition vary depending upon many different factors, including means of administration, target site, physiological state of the subject, whether the subject is human or an animal, other medications administered, and whether treatment is prophylactic or therapeutic. Usually, the subject is a human but non-human mammals including transgenic mammals can also be treated.
In some embodiments, the compositions can be administered to a subject by injection intravenously, subcutaneously, intraperitoneally, intramuscularly, intramedullarily, intraventricularly, intraepidurally, intraarterially, intravascularly, intraarticularly, intrasynovially, intrasternally, intrathecally, intrahepatically, intraspinally, intratumorly, intracranially, enteral, intrapulmonary, transmucosal, intrauterine, sublingual, or locally at sites of inflammation or tumor growth by using standard methods. Alternately, the compositions can be administered to a subject by routes including oral, nasal, ophthalmic, rectal, or topical. The most typical route of administration is intravascular, subcutaneous, or intramuscular, although other routes can be effective. In some embodiments, compositions are administered as a sustained release composition or device, such as a Medipad™ device. The composition can also be administered via the respiratory tract, for example, using a dry powder inhalation device, nebulizer, or a metered dose inhaler. The composition can also be administered by traditional syringes, needleless injection devices, “microprojectile bombardment gone guns,” or other physical methods such as electroporation (“EP”), “hydrodynamic method”, or ultrasound.
In some embodiments, the pharmaceutical compositions may be delivered by intranasal sprays, inhalation, and/or other aerosol delivery vehicles. Methods for delivering genes, nucleic acids, and peptide compositions directly to the lungs via nasal aerosol sprays has been described e.g., in U.S. Pat. Nos. 5,756,353 and 5,804,212 (each specifically incorporated herein by reference in its entirety). Likewise, the delivery of drugs using intranasal microparticle resins (Takenaga et al., 1998) and lysophosphatidyl-glycerol compounds (U.S. Pat. No. 5,725,871, specifically incorporated herein by reference in its entirety) are also well-known in the pharmaceutical arts. Likewise, transmucosal drug delivery in the form of a polytetrafluoroethylene support matrix is described in U.S. Pat. No. 5,780,045 (specifically incorporated herein by reference in its entirety).
In some embodiments, the composition can be administered to a subject by sustained release administration, by such means as depot injections of erodible implants directly applied during surgery or by implantation of an infusion pump or a biocompatible sustained release implant into the subject. Alternately, the composition can be administered to a subject by injectable depot routes of administration, such as by using 1-, 3-, or 6-month depot injectable or biodegradable materials and methods, or by applying to the skin of the subject a transdermal patch containing the composition, and leaving the patch in contact with the subject's skin, generally for 1 to 5 hours per patch.
The present disclosure also provides methods of eliciting an immune response against Mycobacterium tuberculosis in a mammal comprising administering to the mammal an immunologically sufficient amount of one or more CMV vectors comprising one or more of the Mtb fusion proteins described herein.
The fusion proteins and compositions described herein can be used to treat or prevent tuberculosis. In some embodiments, the method comprises administering to a human a therapeutically- or prophylactically-effective amount of any of the CMV vectors or compositions described herein such that the tuberculosis infection is diminished or prevented.
In some embodiments, the subject being treated will have been previously diagnosed as having tuberculosis. Such subjects will, thus, have been diagnosed as being in need of such treatment. Alternately, the treatment may be intended to prevent a tuberculosis infection in a subject that does not yet have tuberculosis or to a subject that is travelling to an area where tuberculosis is prevalent.
Treatment of a subject suffering from tuberculosis can be monitored using standard methods. Some methods entail determining a baseline value, for example, of an antibody level or profile in a subject, before administering a dosage of agent, and comparing this with a value for the profile or level after treatment. A significant increase such as, for example, greater than the typical margin of experimental error in repeat measurements of the same sample, expressed as one standard deviation from the mean of such measurements in value of the level or profile signals a positive treatment outcome (i.e., that administration of the agent has achieved a desired response). If the value for immune response does not change significantly, or decreases, a negative treatment outcome is indicated.
In other embodiments, a control value such as a mean and standard deviation, of level or profile is determined for a control population. Typically the individuals in the control population have not received prior treatment. Measured values of the level or profile in a subject after administering a therapeutic agent are then compared with the control value. A significant increase relative to the control value, such as greater than one standard deviation from the mean, signals a positive or sufficient treatment outcome. A lack of significant increase or a decrease signals a negative or insufficient treatment outcome. Administration of the therapeutic is generally continued while the level is increasing relative to the control value. As before, attainment of a plateau relative to control values is an indicator that the administration of treatment can be discontinued or reduced in dosage and/or frequency.
In other embodiments, a control value of the level or profile, such as a mean and standard deviation, is determined from a control population of individuals who have undergone treatment with a therapeutic agent and whose levels or profiles have plateaued in response to treatment. Measured values of levels or profiles in a subject are compared with the control value. If the measured level in a subject is not significantly different, such as by more than one standard deviation, from the control value, treatment can be discontinued. If the level in a subject is significantly below the control value, continued administration of agent is warranted. If the level in the subject persists below the control value, then a change in treatment may be indicated.
In other embodiments, a subject who is not presently receiving treatment but has undergone a previous course of treatment is monitored for antibody levels or profiles to determine whether a resumption of treatment is required. The measured level or profile in the subject can be compared with a value previously achieved in the subject after a previous course of treatment. A significant decrease relative to the previous measurement, such as greater than a typical margin of error in repeat measurements of the same sample, is an indication that treatment can be resumed. Alternately, the value measured in a subject can be compared with a control value (mean plus standard deviation) determined in a population of subjects after undergoing a course of treatment. Alternately, the measured value in a subject can be compared with a control value in populations of prophylactically treated subjects who remain free of symptoms of disease, or populations of therapeutically treated subjects who show amelioration of disease characteristics. In all of these cases, a significant decrease relative to the control level, such as more than a standard deviation, is an indicator that treatment should be resumed in a subject.
In some methods, a baseline measurement of antibody to a given antigen in the subject is made before administration, a second measurement is made soon thereafter to determine the peak antibody level, and one or more further measurements are made at intervals to monitor decay of antibody levels. When the level of antibody has declined to baseline or a predetermined percentage of the peak less baseline, such as 50%, 25% or 10%, administration of a further dosage of antigen is administered. In some embodiments, peak or subsequent measured levels less background are compared with reference levels previously determined to constitute a beneficial prophylactic or therapeutic treatment regime in other subjects. If the measured antibody level is significantly less than a reference level, such as less than the mean minus one standard deviation of the reference value in population of subjects benefiting from treatment, administration of an additional dosage of antigen is indicated.
Immunization schedules (or regimens) are well known for animals (including humans) and can be readily determined for the particular subject and immunogenic composition. Hence, the immunogens can be administered one or more times to the subject. Preferably, there is a set time interval between separate administrations of the immunogenic composition. While this interval varies for every subject, typically it ranges from 10 days to several weeks, and is often 2, 4, 6 or 8 weeks. For humans, the interval is typically from 2 to 6 weeks. In a particularly advantageous embodiment of the present invention, the interval is longer, advantageously about 10 weeks, 12 weeks, 14 weeks, 16 weeks, 18 weeks, 20 weeks, 22 weeks, 24 weeks, 26 weeks, 28 weeks, 30 weeks, 32 weeks, 34 weeks, 36 weeks, 38 weeks, 40 weeks, 42 weeks, 44 weeks, 46 weeks, 48 weeks, 50 weeks, 52 weeks, 54 weeks, 56 weeks, 58 weeks, 60 weeks, 62 weeks, 64 weeks, 66 weeks, 68 weeks or 70 weeks.
In some embodiments, the subject(s) that can be treated by the above-described methods is an animal, such as a mammal, including, but are not limited to, humans, non-human primates, rodents (including rats, mice, hamsters and guinea pigs) cow, horse, sheep, goat, pig, dog and cat. In most instances, the mammal is a human.
The present disclosure also provides CMV/TB vectors as described herein for use in the preparation of a medicament for treating or preventing a Mycobacterium tuberculosis infection.
The present disclosure also provides CMV/TB vectors as described herein for use in treating or preventing a Mycobacterium tuberculosis infection.
The present disclosure also provides uses of CMV/TB vectors as described herein in the preparation of a medicament for treating or preventing a Mycobacterium tuberculosis infection.
The present disclosure also provides uses of CMV/TB vectors as described herein in treating or preventing a Mycobacterium tuberculosis infection.
The present disclosure also provides any of the CMV/TB vectors as described herein, or any of the compositions described herein, or any of the cells described herein, or any of the methods described herein, or any of the uses described herein, substantially as described with reference to the accompanying examples and/or figures.
The following representative embodiments are presented:
Embodiment 1. A recombinant RhCMV or HCMV vector comprising a nucleic acid sequence encoding an expressible Mtb antigen selected from Ag85A-Ag85B-Rv3407, Rv1733-Rv2626c, RpfA-RpfC-RpfD, Ag85B-ESAT6, and Ag85A-ESAT6-Rv3407-Rv2626c-RpfA-RpfD.
Embodiment 2. The recombinant RhCMV or HCMV vaccine vector of embodiment 1, wherein expression of the Mtb antigen is driven by an antigen-coding sequence in operable association with a promoter selected from the group consisting of a constitutive CMV promoter, an immediate early CMV promoter, an early CMV promoter, and a late CMV promoter.
Embodiment 3. The recombinant RhCMV or HCMV vaccine vector of embodiment 2, wherein the promoter is selected from the group consisting of EF1-alpha, UL82, MIE, pp65, and gH.
Embodiment 4. The recombinant RhCMV or HCMV vaccine vector of any one of embodiments 1 to 3, comprising a deletion or modification of US2, US3, US4, US5, US6, US11, or UL97, or a homolog thereof.
Embodiment 5. The recombinant RhCMV or HCMV vaccine vector of any one of embodiments 1 to 4, comprising a deletion of Rh158-166 or a homolog thereof.
Embodiment 6. The recombinant RhCMV or HCMV vaccine vector of any one of embodiments 1 to 5, wherein the RhCMV or HCMV vaccine vector is a tropism-restricted vector.
Embodiment 7. The recombinant RhCMV or HCMV vaccine vector of embodiment 6, wherein the tropism-restrictive vector lacks genes required for optimal growth in certain cell types or contains targets for tissue-specific micro-RNAs in genes essential for viral replication or wherein the tropism-restrictive vector has an epithelial, central nervous system (CNS), or macrophage deficient tropism, or a combination thereof.
Embodiment 8. The recombinant RhCMV or HCMV vaccine vector of any one of embodiments 1 to 7, wherein the RhCMV or HCMV vaccine vector has a deletion in a gene region non-essential for growth in vivo.
Embodiment 9. The recombinant RhCMV or HCMV vaccine vector of embodiment 8, wherein the gene region is selected from the group consisting of the RL11 family, the pp65 family, the US12 family, and the US28 family.
Embodiment 10. The recombinant RhCMV vaccine vector of embodiment 9, wherein the RhCMV gene region is selected from the group consisting of Rh13-Rh29, Rh111-Rh112, Rh191-Rh202, and Rh214-Rh220, or wherein the RhCMV gene region is selected from the group consisting of Rh13.1, Rh19, Rh20, Rh23, Rh24, Rh112, Rh190, Rh192, Rh196, Rh198, Rh199, Rh200, Rh201, Rh202, and Rh220.
Embodiment 11. The recombinant HCMV vaccine vector of embodiment 9, wherein the HCMV gene region is selected from the group consisting of RL11, UL6, UL7, UL9, UL11, UL83 (pp65), US12, US13, US14, US17, US18, US19, US20, US21, and UL28.
Embodiment 12. The recombinant RhCMV or HCMV vaccine vector of any one of embodiments 1 to 11, wherein the vector comprises a deletion in a RhCMV or HCMV gene that is essential for replication within a host, dissemination within a host, or spreading from host to host.
Embodiment 13. The recombinant RhCMV or HCMV vaccine vector of embodiment 12, wherein the essential gene is UL94, UL32, UL99, UL115, or UL44, or a homolog thereof.
Embodiment 14. The recombinant RhCMV or HCMV vaccine vector of any one of embodiments 1 to 13, wherein the vector comprises a deletion in gene UL82/pp71 or a homolog thereof.
Embodiment 15. The recombinant RhCMV or HCMV vaccine vector of any one of embodiments 1 to 14, wherein the vector further comprises a second nucleic acid sequence encoding US2, US3, or US6, or a homolog thereof, wherein the vector does not encode a functional US11.
Embodiment 16. The recombinant RhCMV or HCMV vaccine vector of embodiment 15, wherein the second nucleic acid sequence encodes US2, US3, and US6.
Embodiment 17. The recombinant RhCMV or HCMV vaccine vector of embodiment 15 or embodiment 16, wherein the nucleic acid encoding a US11 open reading frame is deleted.
Embodiment 18. The recombinant RhCMV or HCMV vaccine vector of any one of embodiment s 15 to 17, further comprising a third nucleic acid sequence encoding US11, and wherein the nucleic acid sequence encoding US11 comprises a point mutation, a frameshift mutation, and/or a deletion of one or more nucleotides of the nucleic acid sequence encoding US11.
Embodiment 19. The recombinant RhCMV or HCMV vaccine vector of embodiment 18, wherein the vector lacks the tegument protein pp65.
Embodiment 20. The recombinant RhCMV or HCMV vaccine vector of any one of embodiments 1 to 19, wherein the vector does not express an active UL130 protein.
Embodiment 21. The recombinant RhCMV or HCMV vaccine vector of any one of embodiments 1 to 20, wherein the RhCMV vaccine vector is Rh68-1 or Rh68-1.2.
Embodiment 22. The recombinant RhCMV or HCMV vaccine vector of embodiment 1 further comprising a microRNA recognition element (MRE) operably linked to a CMV gene that is essential or augmenting for CMV growth, and wherein the MRE silences expression in the presence of a microRNA that is expressed by a cell of myeloid lineage.
Embodiment 23. A pharmaceutical composition comprising the recombinant RhCMV or HCMV vaccine vector of any one of embodiments 1 to 22, and a pharmaceutically acceptable carrier.
Embodiment 24. A method for treatment or prevention of tuberculosis comprising administering to a subject in need thereof at least one recombinant RhCMV or HCMV vaccine vector of any one of embodiments 1 to 22.
Embodiment 25. The method of embodiment 24, further comprising re-administering to the subject at least one recombinant RhCMV or HCMV vaccine vector of any one of embodiments 1 to 22.
Embodiment 26. The method of embodiment 25, wherein the recombinant RhCMV or HCMV vaccine vector of the re-administration is different than the recombinant RhCMV or HCMV vaccine vector of the initial administration.
Embodiment 27. A method for eliciting an immune response to a Mtb antigen comprising administering to a subject in need thereof at least one recombinant RhCMV or HCMV vaccine vector of any one of embodiments 1 to 22.
Embodiment 28. A method for eliciting a CD8+ or CD4+ T cell response to a Mtb antigen comprising administering to a subject in need thereof at least one recombinant RhCMV or HCMV vaccine vector of embodiment 20.
Embodiment 29. The method of any one of embodiments 24 to 28 wherein the recombinant RhCMV or HCMV vaccine vector is administered to the subject intravenously, intramuscularly, intraperitoneally, intranasally, or orally.
Embodiment 30. The method of any one of embodiments 24 to 29 wherein the vector is an HCMV vector and the subject is a human.
Embodiment 31. A Mtb antigen selected from Ag85B-ESAT6 and Ag85A-ESAT6-Rv3407-Rv2626c-RpfA-RpfD.
Embodiment 32. The Mtb antigen of embodiment 31 which is Ag85A-ESAT6-Rv3407-Rv2626c-RpfA-RpfD.
In order that the subject matter disclosed herein may be more efficiently understood, examples are provided below. It should be understood that these examples are for illustrative purposes only and are not to be construed as limiting the claimed subject matter in any manner. Throughout these examples, molecular cloning reactions, and other standard recombinant DNA techniques, were carried out according to methods described in Maniatis et al., Molecular Cloning-A Laboratory Manual, 2nd ed., Cold Spring Harbor Press (1989), using commercially available reagents, except where otherwise noted.
Particular aspects provide recombinant HCMV/TB vectors that can be growth-modulated in vivo (e.g., by oral administration of the antibiotic doxycycline). Heterologous antigen expression may be under the control of promoters of different kinetic classes with respect to the CMV infection cycle (e.g., EF1α—constitutive; MIE—immediate early; pp65—early; gH—late).
In particular embodiments, HCMV/TB vectors lack immune modulatory genes (e.g., Rh158-166 and Rh182-189) to enhance vector immunogenicity, safety and heterologous gene carrying capacity of the vector. For example, HCMV encodes at least four different gene products, gpUS2, gpUS3, gpUS6 and gpUS11 that interfere with antigen presentation by MHC I. All four HCMV MHC evasion molecules are encoded in the unique short region of HCMV and belong to the related US6 gene family. Additional HCMV immunomodulators include, but are not limited to UL118, UL119, UL36, UL:37, UL111a, UL146, UL147, etc. Likewise, RhCMV contains analogous immune modulatory genes, that can be deleted or modified to enhance vector immunogenicity, safety and heterologous gene carrying capacity of the inventive vaccine vectors.
In additional embodiments, HCMV/TB are further optimized for anti-TB immunogenicity by insertion of multiple antigen genes, such as those disclosed herein. Alternatively, several vectors, each having a single inserted antigen may be used for co-administration.
In additional embodiments, HCMV/TB vectors contain LoxP sites strategically placed in the CMV genome to flank an essential region of the viral genome, in combination with a tetracycline (Tet)-regulated Cre recombinase.
The development of BAC technology to clone large segments of genomic DNA coupled with sophisticated λ phage-based mutagenesis systems has revolutionized the field of herpes virology enabling genetic approaches to analyze the virus. Applicants have used this system, for example, to construct an RhCMV BAC(RhCMV BAC-Cre) containing the complete RhCMV strain 68-1 genome. The RhCMV BAC-Cre was derived from an infectious, pathogenic RhCMV 68-1/EGFP recombinant virus. RhCMV BAC-Cre contains a BAC cassette inserted at a single LoxP site within the Rh181 (US1)/Rh182 (US2) intergenic region of RhCMVvLoxP. Insertion of the BAC cassette at this site results in the generation of LoxP sequences flanking the cassette. As the BAC cassette contains a Cre gene that is expressed in eukaryotic cells, transfection of this “self-excising” RhCMV BAC-Cre into fibroblasts results in efficient excision of the BAC cassette, reconstituting virus (designated RhCMVvLoxP). Characterization of the growth of the BAC-reconstituted virus (RhCMVvLoxP) in vitro and in vivo demonstrates that the various genetic manipulations did not alter the WT properties of the virus. The genomic structure of RhCMVvLoxP is identical to that of WT RhCMV except for the residual LoxP site. The presence of the LoxP sequence does not alter the expression profiles of neighboring Rh181 (US1) and Rh182 (US2) or distal (IE2) genes. RhCMVvLoxP replicates with WT kinetics both in tissue culture and in RhCMV seronegative immunocompetent RMs (n=2). Analysis of tissues from one animal terminated at 6 months post-inoculation demonstrated the presence of both RhCMV DNA and IE1-expressing cells in the spleen, consistent with the persistent gene expression observed in previous studies with WT virus. Both RMs developed vigorous anti-RhCMV antibody titers comparable to those observed in naturally infected animals. Taken together, these observations demonstrate that RhCMVvLoxP is phenotypically WT and is suitable to construct site-specific alterations for the development of vaccine vectors.
This challenge included four treatment groups: 1) naive non-human primates (NHPs) (e.g., Rhesus Macaques) (i.e., unvaccinated controls) (n=8); 2) NHPs vaccinated with BCG alone (n=7); 3) NHPs vaccinated with a cocktail of CMV/TB vectors alone (n=7); and 4) NHPs vaccinated with BCG and a cocktail of CMV/TB vectors. The naive NHPs were CMV-seropositive. The NHPs vaccinated with BCG were vaccinated with 0.1 ml intradermally with Statens Serum Institute (SSI) BCG vaccine. The NHPs vaccinated with a cocktail of CMV/TB vectors were vaccinated with four Rh68-1 vectors (encoding fusion proteins comprised of Ag85A-Ag85B-Rv3407, Ry1733-Rv2626, RpfA-RpfC-RpfD, and Ag85B-ESAT6). The NHPs vaccinated with BCG and a cocktail of CMV/TB vectors were primed with the SSI BCG and boosted with the same cocktail of the four Rh68-1 vectors as above. The NHPs who received the CMV/TB vectors received 5×106 PFU (plaque forming unit) of CMV/TB vector cocktails subcutaneously at weeks 6 and 21. The two BCG groups were given BCG at Week 0. At Weeks 6 and 21, the two CMV/TB vectors groups were immunized with the cocktail of RhCMV/TB vectors. NHP were challenged with Mycobacterium tuberculosis at Week 49. Endpoints included longitudinal CT scanning, gross pathology and bacterial burden.
Three of the four vectors used in this study encode classical, latency and resuscitation antigen cassettes (encoding fusion proteins comprised of Ag85A-Ag85B-Rv3407, Rv1733-Rv2626, and RpfA-RpfC-RpfD, respectively). NHP received 5E6 pfu/RhCMV vector, delivered subcutaneously. Also included was a Rh68-1 vector encoding a fusion protein comprised of Ag85AB and ESAT6.
Immunogenicity of these vectors was evaluated using intracellular cytokine staining.
The RhCMV vectors were highly immunogenic, showing robust responses in both peripheral blood mononuclear cells (PBMCs) as well as bronchoalveolar lavage (BAL). Vaccination with Rh68-1 also significantly reduced disease progression as compared to naive controls.
Efficacy was evaluated by several means, including CT scan analysis (volume of lung involvement), necropsy score (size, number and distribution of gross lesions; lung, lung-draining lymph nodes, and total (which includes distant dissemination)), and necropsy Mycobacterium tuberculosis cultures (40 lung samples by sterology (30 right; 10 left); 9 lymph nodes (6 lung draining and 3 non-mediastinal); and 9 extra-pulmonary tissues (5 liver, 2 kidney, spleen, and pancreas)).
For pulmonary necropsy scoring, individual lobes were scored on 5 mm sections. The following scores were given for granuloma prevalence: no visible lesions=1; 1-3 lesions=2; 4-10 lesions=3; 11-15 lesions=4; 16-20 lesions=5; >20 lesions=6; and Miliary<50% of lobe=7. The following scores were given for largest granuloma size: none visible=1; <1-2 mm=2; 3-4 mm=3; 5-10 mm=4; 11-20 mm=5; >20 mm=6; confluent or miliary lesions involving <50% of lobe=7; and confluent or miliary lesions involving >50% of lobe=8. The following scores were given for additional scoring criteria (1=absent; 2=present): parietal pleural adhesions associated with granulomatous disease, parietal pleural thickening associated with granulomatous disease; granulomatous disease with cavitation, and granulomatous disease involving parietal pleura, diaphragm or body wall.
For thoracic lymph node necropsy scoring, the following scores were given for size: nodes visible but not enlarged (≤5 mm)=0; nodes visibly enlarged (≤5-10 mm) (unilateral)=1; nodes visibly enlarged (≤5-10 mm) (bilateral)=2; and nodes visibly enlarged (>1 cm) (unilateral/bilateral)=3. The following scores were given for granuloma prevalence: no granulomas visible on capsular or cut surface=0; focal or multifocal, circumscribed, non-coalescing granulomas <2 mm=1; coalescing solid or caseous granulomas occupying <50% of node=2; coalescing solid or caseous granulomas occupying >50% of node=3; and complete granulomatous nodal effacement=4. The following scores were given for additional scoring criteria (absent=1; present=2): other thoracic lymph nodes.
For liver and spleen necropsy scoring, the following scores were given for prevalence: no visible granulomas=0; 1-3 visible granulomas=1; 4-10 visible granulomas=2; >10 visible granulomas=3; and miliary pattern=4. The following scores were given for granuloma size: none present=0; <1-2 mm=1; 3-4 mm=2; and >4 mm=3.
For miscellaneous organs and tissue, the following scores were given for prevalence: no visible granulomas=0; 1-3 visible granulomas=1; 4-10 visible granulomas=2; >10 visible granulomas=3; and miliary pattern=4. The following scores were given for granuloma size: none present=0; <1-2 mm=1; 3-4 mm=2; and >4 mm=3.
In general, CMV vectors elicit and maintain higher TB insert-specific CD4+ and CD8+ T cell responses than BCG. These responses are associated with significant protection against both pulmonary and extra-pulmonary disease progression. BCG was associated with, at best, a trend towards modest pulmonary protection, but extra-pulmonary disease was no different than that of unvaccinated controls. Indeed, the administration of BCG prior to CMV vector vaccination partially abrogated CMV vector-mediated protection, in particular for extra-pulmonary spread. T cell responses to some, but not all, TB inserts were lower in some tissues in the animals receiving both BCG and CMV vectors compared to those receiving CMV vectors alone, but it remains to be determined whether this or another mechanism (e.g., BCG elicited responses promoting bacterial spread) account for the reduced protection associated the BCG “prime.” Correlates of protection were stronger for extra-pulmonary disease than pulmonary disease and point to RpfA, RpfD, Ag85A, Rv2626 and Rv3407 (and possibly ESAT6) being the most effective vaccine inserts.
In summary, RhCMV/TB vector-vaccinated RM show significantly reduced disease (both pulmonary and extra-pulmonary) by all criteria. RhCMV/TB vectors elicited and maintained higher (and qualitatively different) TB insert-specific CD4+ and CD8+ T cell responses than BCG. RhCMV/TB vector vaccination provided significant protection against both pulmonary and extra-pulmonary disease progression (73% overall). BCG was associated with a trend towards modest pulmonary protection compared to unvaccinated controls, but extra-pulmonary disease was no different than that of unvaccinated controls. The combination of BCG and RhCMV/TB vectors is less effective than RhCMV/TB vector vaccination alone with the BCG component reducing both pulmonary and extra-pulmonary protection. RhCMV/TB vector-vaccinated RM may manifest a marked enhanced early response to infection in carinal LNs. The outcome (extra-pulmonary spread) predominantly correlated with CD4+ T cell responses to Ag85A, Rpf-A/C/D, Rv3407, Rv2626, and ESAT6.
The second study was designed to confirm and extend previous findings of CMV-induced protection against Mycobacterium tuberculosis in rhesus macaques. In the original study, significant protection was induced by a cocktail of CMV vectors (strain 68-1), encoding a total of 9 antigens.
The second NHP study consisted of four vaccine groups: 1) Strain 68-1 RhCMV/TB-9Ag vector set (n=9); 2) Strain 68-1.2 RhCMV/TB-9Ag vector set (n=9); 3) Strain 68-1 RhCMV/TB-6Ag single vector (n=9); and 4) unvaccinated. Group 1) consisted of Macaques vaccinated with a cocktail of four Rh68-1 vectors (encoding fusion proteins comprised of Ag85A-Ag85B-Rv3407, Rv1733-Rv2626, RpfA-RpfC-RpfD, and Ag85B-ESAT6). Group 2) consisted of Macaques vaccinated with a cocktail of four Rh68-1.2 vectors (encoding fusion proteins comprised of Ag85A-Ag85B-Rv3407, Rv1733-Rv2626, RpfA-RpfC-RpfD, and Ag85B-ESAT6). Group 3) consisted of Macaques vaccinated with a single Rh68-1 vector (encoding a fusion protein comprised of Ag85A-ESAT6-Rv3407-Rv2626c-RpfA-RpfD).
At weeks 0 and 14, NHP in Groups 1)-3) were vaccinated with the RhCMV/TB vectors described above. NHP were challenged with Mycobacterium tuberculosis (Erdman E11-10 mTB at 10 CFU given intrabronchially) at week 55. There was not BAL post-challenge. The outcomes analyzed were the same as those described above in Example 2.
The 4 Rh68-1 vectors used in the first study were used again here (see above for information on construction). Three of the four Rh68-1.2 vectors used in this study encode classical, latency and resuscitation antigen cassettes (encoding fusion proteins comprised of Ag85A-Ag85B-Rv3407, Rv1733-Rv2626, and RpfA-RpfC-RpfD, respectively). The Rh68-1 vector encoding a six-antigen fusion protein (comprising antigens Ag85A, ESAT6, Rv3407, Rv2626, RpfA and RpfD) and Rh68-1.2 vector encoding Ag85B and ESAT6 were also used.
Immunogenicity of these vectors was evaluated using intracellular cytokine staining.
In summary, low dose (10 bacteria) Erdman E11-10 strain mTB challenge resulted in considerably less aggressive disease than previous studies using a >25 bacteria challenge dose, but all unvaccinated controls still showed both pulmonary and draining LN disease. Strain 68-1 RhCMV/TB vector vaccination, either the 9 Ag vector set, or the single 6 Ag insert vector, provided striking protection against both pulmonary and extra-pulmonary disease after low dose mTB challenge: 1) 10 of 18 NHPs (56%) with no pathologic evidence of infection (7 of which were also completely culture negative) vs. 0% of unvaccinated controls; and 2) 12 of 18 NHPs (67%) with less disease (as measured by both Path Score and Culture) than the unvaccinated control with the least extent of disease progression; and 3) efficacy of the Strain 68-1 RhCMV/TB-6Ag single vector ≥Strain 68-1 RhCMV/TB-9Ag vector set. Strain 68-1.2 RhCMV/TB-9Ag vaccination resulted in significant overall protection.
In addition, Strain 68-1 RhCMV/TB vector vaccination protects highly TB susceptible rhesus macaques from progressive pulmonary and extra-pulmonary TB disease after both high and low dose intrabronchial Erdman strain mTB challenge. In the high dose challenge model, BCG was not significantly protective and the combination of BCG and Strain 68-1 RhCMV/TB vector vaccination was less protective than Strain 68-1 RhCMV/TB vector vaccination alone. Current data suggest vector-elicited CD4+ T cell responses are the primary protective correlate. To date, the single 6 Ag (polyprotein) expressing RhCMV vector provides the best overall protection, but it remains possible that different or additional TB Ag inserts would increase efficacy.
RM were sedated with ketamine HCl or Telazol® for intradermal and subcutaneous vaccine administration, venipuncture, bronchoalveolar lavage, lymph node biopsy, intrabronchial Mtb inoculation and computed tomography (CT) procedures. Mtb Erdman K01 was diluted in saline, lightly sonicated and bacteria were delivered to a segmental bronchus in the right caudal lung lobe using a bronchoscope. The RM in Studies 3 and 4 received 25 and 10 colony forming units (CFU), respectively, in a volume of 2 ml. Pre- and post-challenge axial CT scans (2.5 mm slices) were obtained using a multi-section CT scanner using helical technique, collimation 3 mm and pitch 1.5 (CereTom, Neurologica Corp., Danvers, MA) and reconstructed as 1.25 mm slices to improve detection sensitivity. Nonionic iodinated contrast (Isovue 370, 1-2 ml/kg, Bracco Diagnostics, Princeton NJ) was administered IV at a rate of 1-2 ml/s. CT scans were obtained with 120 kVp and 200 mA. All animals were imaged pre-challenge, at two-week intervals for the duration of the studies and immediately prior to necropsy. Scans were interpreted by a veterinarian who was blinded to the identity of the subject. Lesion area in sequential scans was determined from transverse slices through entire lung fields using the IMPAX 6.5.5.3020 software area tool (AGFA HealthCare N.V., Mortsel, Belgium) and lesion volume determined by multiplying area by 1.25. One RM developed extensive bilateral miliary disease with estimated lesion volume >200,000 mm 3 and no further attempts to estimate lesion volume were made in this animal.
The humane criteria for removing RM with end-stage TB from the studies are as follows: 1) marked lethargy, 2) severe dyspnea at rest and/or failure to maintain adequate oxygenation (85%) based on pulse oximetry or blood gas analysis, 3) hemoptysis, 4) weight loss (>15% in 2 weeks; >25% over any time course in an adult animal), 5) hypothermia <96° F. with supplemental heating, 6) persistent anemia (<20% for 2 weeks), 7) dehydration unresponsive to oral rehydration therapy for 3 days, 8) non-responsiveness to therapy for spontaneous diseases conditions, 9) poor appetite, requiring more than 3 orogastric tube feedings in 7 days, 10) obtundation, 11) neurologic deficits, and 12) persistent self-injurious behavior unresponsive to a change in location or enrichment. RM that manifested one or more of these end-stage criteria were immediately necropsied. RM that remained clinically well after post-infection week 16 were randomized and scheduled for euthanasia and necropsy at the rate of two per week. There were 3 exceptions to this general rule of necropsy initiated by end-stage disease criteria or randomization (designated as “other”). One non-end-stage RM (D1) in Study 3 was euthanized on the same day as an end-stage RM because the IACUC does not permit housing a single RM alone in a room. Two additional RM (N1, N3) in Study 3 were euthanized because of failure to maintain adequate oxygenation following a bronchoalveolar lavage procedure that was not attributable to end-stage Mtb disease. To avoid this issue in Study 4, BALs were not performed after challenge in this study.
At the humane or scheduled endpoint RM were euthanized with sodium pentobarbital overdose (>50 mg/kg) and exsanguinated via the distal aorta. The necropsy procedure included complete gross pathologic evaluation of abdominal organs and tissues and the brain prior to entering the thoracic cavity to avoid contamination. Macroscopic granulomas in liver, spleen, kidney and the brain were counted, measured and photographed in serial 5 mm tissue slices whereas granulomas occurring in extra thoracic lymph nodes, the gastrointestinal tract and soft tissues were collected, measured and photographed with minimum sectioning and given a numeric point value score using a semi-quantitative grading system (see,
The 68-1 and 68-1.2 RhCMV/TB vectors were constructed by bacterial artificial chromosome (BAC) recombineering and were reconstituted and amplified into vector preparations as previously described (Hansen et al., Nature, 2011, 473, 523-527; Hansen et al., Nature, 2013, 502, 100-104; Hansen et al., Science, 2013, 340, 1237874; and Hansen et al., Nat. Med., 2009, 15, 293-299). The Mtb Ags to be included in these vectors were selected by a bioinformatics selection criteria starting with the scoring of 4000 Mtb open reading frames by 11 criteria (Zvi et al., BMC Med. Genomics, 2008, 1, 18). Those criteria included immunogenicity, vaccine efficacy, expression in granulomas, secretion, and role in hypoxic survival. The top candidates were then further screened by a deeper bioinformatics analysis of predicted T cell epitopes and curated to include antigens that are active during different stages of TB infection. In addition, all antigens had been shown to be at least partially protective in a mouse challenge model. The final choice of 9 Mtb proteins for the vaccine inserts included 3 representative proteins from so-called acute phase (85A, 85B, ESAT6), latency (Rv1733c, Rv3407, Rv2626c) and resuscitation (Rpf A, Rpf C and RpfD) class of Mtb Ags. These 9 Ags were expressed in 4 different RhCMV/TB vectors (to be used in combination) for both the 68-1 and 68-1.2 backbones, as follows: 1) Ag85A/Ag85B/Rv3407 (GenBank #KY611401), 2) Rv1733/Rv26226 (GenBank #KY611402), 3) RpfA/RpfC/RpfD (GenBank #KY611403), and 4) Ag85B/ESAT-6 (GenBank #KY611404). The GenBank Accession #s correspond the to the sequences as they are found in the final vectors. Polyprotein #s 1-3 were inserted into the nonessential Rh211 open reading frame under the control of murine CMV IE promotor. Polyprotein #4 was inserted in the same region of the RhCMV genome but under the control of the EF1α promotor (see,
Mtb-specific CD4+ and CD8+ T cell responses were measured in blood, BAL and tissues by flow cytometric ICS, as previously described (Hansen et al., Science, 2013, 340, 1237874; Hansen et al., Science, 2016, 351, 714-720; and Hansen et al., Nat. Med., 2009, 15, 293-299). Briefly, mononuclear cell preparations from blood, BAL or tissue were incubated at 37° C. in a humidified 5% CO2 atmosphere with overlapping, consecutive 15-mer peptide mixes (11 amino acid overlap) comprising these proteins, or individual 15-mer peptides from these proteins, and the co-stimulatory molecules CD28 and CD49d (BD Biosciences) for 1 hour, followed by addition of brefeldin A (Sigma-Aldrich) for an additional 8 hours. Co-stimulation without antigenic peptides served as a background control. As previously described (Hansen et al., Science, 2016, 351, 714-720), the MHC restriction (MHC-Ia, MHC-E, MHC-II) of a peptide-specific response was determined by pre-incubating isolated mononuclear cells for 1 hour at room temperature (prior to adding peptides and incubating per the standard ICS assay) with the following blockers: 1) the pan anti-MHC-I mAb W6/32 (10 mg/ml), 2) the MHC-II-blocking CLIP peptide (MHC-II-associated invariant chain, amino acids 89-100; 20 μM), and 3) the MHC-E-blocking VL9 peptide (VMAPRTLLL; SEQ ID NO:31; 20 μM). Blocking reagents were not washed, but remain throughout the assay. Following incubation, stimulated cells were fixed, permeabilized and stained as previously described (Hansen et al., Science, 2013, 340, 1237874; Hansen et al., Science, 2016, 351, 714-720; and Hansen et al., Nat. Med., 2009, 15, 293-299) using combinations of the following fluorochrome-conjugated mAbs: SP34-2 (CD3; Pacific Blue, Alexa700), L200 (CD4; AmCyan, BV510), SK-1 (CD8α; PerCP-Cy5.5), MAB11 (TNF-α; FITC, PE), B27 (IFN-γ; APC), FN50 (CD69; PE, PE-TexasRed), B56 (Ki-67; FITC), and in polycytokine analyses, JES6-5H4 (IL-2; PE, PE Cy-7). To determine the cell surface phenotype of Mtb-specific CD8+ T cells, mononuclear cells were stimulated as described above, except that the CD28 co-stimulatory mAb was used as a fluorochrome conjugate to allow CD28 expression levels to be later assessed by flow cytometry, and in these experiments, cells were surface-stained after incubation for lineage markers CD3, CD4, CD8, CD95 and CCR7 (see below for mAb clones) prior to fixation/permeabilization and then intracellular staining for response markers (CD69, IFN-γ, TNF-α). Data was collected on an LSR-II (BD Biosciences). Analysis was performed using FlowJo software (Tree Star). In all analyses, gating on the lymphocyte population was followed by the separation of the CD3+ T cell subset and progressive gating on CD4+ and CD8+ T cell subsets. Antigen-responding cells in both CD4+ and CD8+ T cell populations were determined by their intracellular expression of CD69 and one or more cytokines (either or both of the IFN-γ and TNF; ±IL-2 in polycytokine analyses). After subtracting background, the raw response frequencies were memory corrected, as previously described (Hansen et al., Nature, 2011, 473, 523-527 and Hansen et al., Nat. Med., 2009, 15, 293-299) using combinations of the following fluorochrome-conjugated mAbs to define the memory vs. naive subsets SP34-2 (CD3; Alexa700, PerCP-Cy5.5), L200 (CD4; AmCyan), SK-1 (CD8α; APC, PerCP-cy-5.5), MAB11 (TNF-α; FITC), B27 (IFN-γ; APC), FN50 (CD69; PE), CD28.2 (CD28; PE-TexasRed), DX2 (CD95; PE), 15053 (CCR7; Pacific Blue), and B56 (Ki-67; FITC). For memory phenotype and polycytokine analysis of Mtb Ag-specific T cells, all cells expressing CD69 plus one or more cytokines were first Boolean gated, and then this overall Ag-responding population was subdivided into the subsets of interest on the basis of surface phenotype or cytokine production pattern.
Tissues routinely collected at necropsy for Mtb burden analysis in both Study 3 and 4 included: 30 stereologic punches from right lung lobes, 10 punches from left lung lobes, trachea, left hilar LN, right hilar LN, left carinal LN, right carinal LN, paratracheal LN, mediastinal LN, axillary LN, inguinal LN, mesenteric LN, spleen, pancreas, left medial lobe of liver, right medial lobe of liver, left lateral lobe of liver, right lateral lobe of liver, liver caudate, left kidney, and right kidney. In Study 4, retropharyngeal LN, tonsil, submandibular LN, and iliosacral LN were also collected and cultured. In one RM in Study 4, mycobacterial culture analysis was not reported due to gross contamination of thoracic tissues with granuloma contents. Tissues were collected in HBSS and were then homogenized in an IKA grinder tube with a IKA Ultra-Turrax Tube Drive homogenizer. The tissue homogenate was then filtered over a 70 vim wire screen to remove debris and 200 μl of this material was plated neat and in serial dilutions ( 1/10, 1/100) on 7H11 agar plates (Remel). All plates were incubated at 37° C. and M. tuberculosis growth was enumerated 28 and 42 days later. Bacterial burden was calculated in CFU per gram of tissue. A tissue was considered Mtb+ if any colonies with the correct morphologic features were identified. Selected cultures were analyzed by the Ziehl-Neelsen method for acid-fast bacteria to confirm colony morphologic features.
Three outcome measures were evaluated for evidence of a difference across treatment arms within each study: CT scan area-under the curve from challenge to day 112 post-challenge, pathologic score at necropsy, and Mtb culture at necropsy. The equivalence of the three Study 4 vaccine groups by these outcome measures (see,
Area under the log CT scan-determined pulmonary disease volume curve: The AUC of the log-transformed CT scan-determined pulmonary disease volume measurements from time 0 (set to 0) to day 112 was computed. Missing values for monkeys taken to necropsy before the full series of scheduled CT scan time points were imputed. The AUC of this augmented data was computed. The imputation procedure that was employed used linear regression to estimate missing values from previous time points. As a sensitivity analysis, the missing values were imputed using a more conservative rule (replacing missing values with the largest non-missing value at the same time point among monkeys receiving the same treatment, excluding for further conservatism one high-valued outlier unvaccinated RM); the resulting AUCs were highly insensitive to this procedure (Pearson correlation over 0.99 for both studies).
Necropsy score data: The non-negative count valued necropsy scores are amenable to Poisson modeling. Model evaluations supported inclusion of the additional parameter for overdispersion in the negative binomial model. In TB Study 4, the estimated extra parameter was zero, so this model was equivalent to a simple Poisson model. For this Poisson model, a sandwich-based estimates of variance-covariance matrices was employed as an alternative method to account for overdispersion, using the vcovHC function in the sandwich package (Zeileis, J. Stat. Software, 2004, 11, 1-17 and Zeileis, J. Stat. Software, 2006, 16, 1-16) in R.
Necropsy culture data: Necropsy culture inputs were quantitative measures of culture growth with multiple replicates per tissue. These data were treated as binary indicators of a culture being positive versus negative (zero), and the total number of positive cultures was evaluated. Model evaluations of necropsy culture outcome data favored the more expressive negative binomial models over Poisson models, and did not support using the ZIP model. One animal in TB Study 4 (Rh30072) was missing necropsy culture data but did have necropsy score data; the analyses of the culture data therefore excluded this RM, but as described below, the missing value for use in computing the combined scaled outcome measure was imputed.
Combined scaled outcome measure: As shown in
End of vaccine phase T cell response data: Longitudinal flow cytometric ICS measures of CD4+ and CD8+ immune responses targeting the 9 individual genes in the RhCMV vaccines, and CFP10 was evaluated. The primary summary of these data was a measure of the immune response at the end of vaccine phase. These pre-challenge baseline immunogenicity values are geometric means of three independent measurements over the time periods shown in
All statistical analyses were conducted in R40.
Efficacy: Non-parametric tests were employed for primary comparisons and parametric models were used for estimating confidence intervals of treatment effects. For comparisons of outcome measures across pairs of groups, we used two-sided Wilcoxon tests. Boxplots show unadjusted p-values of only the pairwise comparisons that are significant at the 0.05 level. Holm adjustment was employed for the specified primary non-parametric comparisons: between unvaccinated and vaccinated TB Study 3 groups, and separately between BCG-only and other vaccinated groups. For TB Study, 4 similarly applied Holm-adjustment within groups of comparisons between unvaccinated and vaccinated TB Study 4 groups individually, and between the original 68-1 9Ag vector and the two modifications (68-1 6Ag, and 68-1.2 9Ag). Boxplots show unadjusted p-values; Holm-adjusted p-values are shown in
Immunogenicity and correlates analysis: For comparisons of immunogenicity across vaccine-receiving treatment groups at pre-challenge baseline, Kruskal-Wallis (KW) tests were employed. The boxplots indicate significance of pairwise Wilcoxon tests if both KW and Wilcoxon tests had unadjusted p-values <0.05. Due to the missing of blood immunology data from week 41 of RM U6 (Study 3; BCG-only group), for
To initially test the hypothesis that TEM responses elicited by RhCMV/TB vectors would manifest a higher efficacy than BCG, 3 groups of RM (n=7 each; all naturally RhCMV-infected at study assignment) were vaccinated with: 1) RhCMV/TB vectors alone (a set of 4 RhCMV vectors based on the 68-1 strain that together express 9 different Mtb proteins: ESAT-6, Ag85A, Ag85B, Rv3407, Rv1733, Rv2626, Rpf A, Rpf C, Rpf D; see,
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Fifty weeks after initial vaccination, the 3 groups of vaccinated RM and a control group of unvaccinated RM (n=8; also naturally CMV+) were challenged by intrabronchial instillation of 25 colony-forming units (CFUs) of Erdman strain Mtb bacteria into the right lower lobe. The effectiveness of challenge was confirmed by de novo development of CD4+ and CD8+ T cell responses to the CFP-10 Ag in all RM (see,
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The CT-determined lesional AUC through week 16 pi closely correlated with pulmonary parenchymal disease at necropsy as measured by both pathologic scoring and Mycobacteria culture (see,
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To confirm and further characterize RhCMV/TB efficacy, a second, larger Mtb challenge study (n=9 RM per group; all RhCMV+ at assignment) was performed using a lower dose of Erdman strain and in which we compared the same 68-1 RhCMV/TB-9 Ag vaccine used in Study 3 (group 1) with an analogous RhCMV/TB-9 Ag) vaccine based on the 68-1.2 vector backbone (in which repaired expression of Rh157.5 and Rh157.4 results in distinct CD8+ T cell epitope targeting; group 2), and a single 68-1 RhCMV/TB-6 Ag vector expressing a 6-Ag Mtb polyprotein (Ag85A; ESAT-6; Rv3407; Rv2626; Rpf A; Rpf D) (group 3) (see,
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After a 56 week vaccination period, all 27 vaccinated RM in groups 1-3 and 9 RhCMV+unvaccinated control RM (group 4) were intrabronchially challenged with 10 CFUs of Erdman strain Mtb bacteria—the reduction in dose relative to Study 3 intended to slow TB progression in Study 4 RM to more closely resemble the course of human Mtb infection. In addition, post-challenge BAL was not performed in this experiment to prevent procedure-related mortality or enhancement of bacteria spread within the lung. All RM developed de novo CFP-10-specific T cell responses in blood following challenge, and the RhCMV/TB-6 Ag-vaccinated RM (group 3) also developed de novo T cell responses in blood to the Ag85B, Rpf C, and Rv1733 Ags, which were not included in their vaccine (see,
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It is remarkable that despite the fact that the average extent of TB progression in the unvaccinated control monkeys in Studies 3 and 4 was quite different, the reduction in disease with RhCMV/TB vaccination was similar in both studies. Indeed, using a normalized, combination outcome parameter based on both mycobacterial culture and pathologic score, it was estimated that across both studies the extent of disease in the RhCMV/TB-vaccinated RM was reduced 68% relative to unvaccinated controls (P=0.0019) (see,
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These studies show that a parenterally administered RhCMV-based vaccine is able to elicit and maintain over the course of at least a year effector responses that can control Mtb at the early stages of infection, and that the protection afforded by this vaccine can be complete, if not sterilizing. To our knowledge, this is the first report of complete prevention of TB in the RM model. Given TEM responses to natural, persistent CMV infection are maintained for life, the protection afforded by this vector platform is likely to be very durable, probably lifelong. The RhCMV/TB vaccine is efficacious against aggressive TB in RM and provides treatment of a human CMV/TB vaccine that would be effective in preventing pulmonary TB in adolescents and adults, and thereby contribute to ending the global TB epidemic.
Over both Studies 3 and 4, RhCMV/TB vaccination reduced the extent of disease at necropsy, as measured by both pathologic score and frequency of mycobacterial culture-positive tissues, by 68% compared to unvaccinated controls (P=0.0019). There was no significant difference in efficacy between cohorts vaccinated with 68-1 vs. 68-1.2 RhCMV vector backbones (which differ in CD8+ T cell epitope recognition) or with 68-1 RhCMV vectors expressing 9 vs. 6 Mtb proteins. In contrast, BCG was not significantly efficacious in this challenge model, and administration of BCG 6 weeks prior to RhCMV/TB vaccination reduced the efficacy of the latter vaccine. Across both studies, 14 of the 34 RhCMV/TB-vaccinated RM (41%) showed no granulomatous disease at necropsy (vs. 0 of 17 unvaccinated controls; P=0.0018), despite immunologic evidence of initial infection after challenge, and 10 of these were mycobacterial culture-negative in all tissues. Thus, the RhCMV/TB vaccine is superior to BCG in the RM model, and is the first vaccine demonstrated to completely prevent progressive TB in primates.
Various modifications of the described subject matter, in addition to those described herein, will be apparent to those skilled in the art from the foregoing description. Such modifications are also intended to fall within the scope of the appended claims. Each reference (including, but not limited to, journal articles, U.S. and non-U.S. patents, patent application publications, international patent application publications, gene bank accession numbers, and the like) cited in the present application is incorporated herein by reference in its entirety.
This application claims priority to U.S. Provisional Application Ser. No. 62/353,432 filed Jun. 22, 2016 and U.S. Provisional Application Ser. No. 62/478,099 filed Mar. 29, 2017, each of which is incorporated herein by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 62478099 | Mar 2017 | US | |
| 62353432 | Jun 2016 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 17365509 | Jul 2021 | US |
| Child | 18496076 | US | |
| Parent | 15628921 | Jun 2017 | US |
| Child | 17365509 | US |
